ThinkPad 750 / 755 and 370C

Thirteen variants side by side, compiled from a hardware survey and IBM's product records. A value spanning several columns applies to each of those variants; a dash means no source records it.

IBM model codes — 169 models of machine type 9545

Variant	Model codes
ThinkPad 755CD	9545-CD6, 9545-CD7, 9545-F3K, 9545-F3L, 9545-FBK, 9545-FBL, 9545-FFK, 9545-FFL, 9545-FHK, 9545-FHL, 9545-FNK, 9545-FNL, 9545-FPK, 9545-FPL, 9545-FQK, 9545-FQL
ThinkPad 755CX	9545-CX3, 9545-H3L, 9545-HBL, 9545-HDL, 9545-HFL, 9545-HHL, 9545-HNL, 9545-HPL, 9545-HQL
ThinkPad 755CV	9545-CV5, 9545-CV6, 9545-EBK, 9545-EBL, 9545-ENK, 9545-ENL, 9545-EPK, 9545-EPL
ThinkPad 755CDV	9545-DV5, 9545-DV6, 9545-G3K, 9545-G3L, 9545-GBK, 9545-GBL, 9545-GFK, 9545-GFL, 9545-GNK, 9545-GNL, 9545-GPK, 9545-GPL
Variant not recorded	9545-6BC, 9545-6BD, 9545-6BE, 9545-750, 9545-7BC, 9545-7BD, 9545-7BE, 9545-7DD, 9545-7NC, 9545-7ND, 9545-7NE, 9545-7PC, 9545-7PD, 9545-7PE, 9545-8BJ, 9545-8NJ, 9545-8PK, 9545-9BD, 9545-9BE, 9545-9ND, 9545-9NE, 9545-9PD, 9545-9PE, 9545-A3K, 9545-ABJ, 9545-ABK, 9545-AFK, 9545-ANJ, 9545-ANK, 9545-APJ, 9545-APK, 9545-CD3, 9545-CD4, 9545-CE2, 9545-CE3, 9545-CE4, 9545-CV1, 9545-CV2, 9545-CX1, 9545-CX2, 9545-CX4, 9545-CX5, 9545-CX6, 9545-DS1, 9545-DS2, 9545-DS5, 9545-DS6, 9545-DV1, 9545-DV2, 9545-DV3, 9545-E0C, 9545-E0E, 9545-E0G, 9545-ECE, 9545-EYC, 9545-EYE, 9545-F0C, 9545-F0E, 9545-F0G, 9545-F3C, 9545-F3E, 9545-FJ6, 9545-FJ8, 9545-FJA, 9545-FMC, 9545-FME, 9545-FYC, 9545-FYE, 9545-FZE, 9545-H3E, 9545-HBD, 9545-HBE, 9545-HFE, 9545-HNE, 9545-K0C, 9545-K0E, 9545-KZC, 9545-KZE, 9545-KZG, 9545-L0C, 9545-L0E, 9545-L0G, 9545-LCE, 9545-LJC, 9545-LJE, 9545-LJG, 9545-LJK, 9545-LJM, 9545-LYE, 9545-LYG, 9545-LZC, 9545-LZE, 9545-LZG, 9545-Q3D, 9545-QDD, 9545-QFC, 9545-QFD, 9545-QFJ, 9545-QHC, 9545-QHD, 9545-QNC, 9545-QND, 9545-QNE, 9545-QPC, 9545-QPD, 9545-QQC, 9545-QQD, 9545-S3J, 9545-S3K, 9545-SBJ, 9545-SBK, 9545-SDJ, 9545-SFJ, 9545-SFK, 9545-SNJ, 9545-SNK, 9545-SPJ, 9545-SPK, 9545-TC1, 9545-TC2, 9545-TF4, 9545-TF5, 9545-TF6, 9545-TF7

This hardware maintenance manual covers information about the following IBM ThinkPad models:

• 355, 360, 750 (monochrome)
• 355C, 360C, 360CE, 370C, 750C, 755C (TFT color)
• 750Ce (TFT color, enhanced)
• 355Cs, 360Cs, 360CSE, 750Cs, 755Cs (STN color)
• 360P, 360PE, 750P (pen).

When information affects only a specific model, the model number is shown in parenthesis in the heading or is explained in the text. Before you go to the checkout guide, be sure to read this section.

• Be extremely careful during write operations such as copying, saving, or formatting. Drives in the computer that you are servicing might have been rearranged or the drive startup sequence might have been altered. If you select an incorrect drive, data or programs can be written over.
• Replace FRUs only for the correct model. When you replace the FRU, make sure the model of the machine and FRU part number are correct by referring to the part list.
• FRUs should not be replaced because of a single, un-reproducible failure. Single failures can occur from a variety of reasons that have nothing to do with a hardware defect such as: cosmic radiation, electrostatic discharge, or software errors. FRU replacement should only be considered when a recurring problem exists. If this is suspected, clear the error log and run the test again. Do not replace any FRUs if log errors do not reappear.

The servicer must include the following in the parts exchange form or part return form that is attached to the returned FRU.

1. Name and phone number of servicer.
2. Date of service.
3. Date when part failed.
4. Date of purchase.
5. Failure symptoms, error codes appearing on display, and beep symptoms.
6. Procedure index and page number in which failing FRU was detected.
7. Failing FRU name and part number.
8. Machine type, model number, and serial number.
9. Customer's name and address.

Before checking problems with the computer, determine whether or not the damage applies to the warranty by referring to the following:

Note for Warranty: During the warranty period, the customer may be responsible for repair costs if the damage was caused by misuse, accident, modification, unsuitable physical or operating environment, or improper maintenance by the customer.

The following list provides some common items that are not covered under warranty and some symptoms that could indicate that the system was subjected to stresses beyond normal use.

If the following symptoms are present, they could indicate the damage was caused by non-warranted activity:

• Missing parts can be a symptom of unauthorized service or modification.
• HDD spindles can become noisy if subjected to excessive force or is dropped.
• I9990303 errors can be caused by exposure to strong magnetic fields.

How to Use Error Messages

Use the error codes displayed on the screen to diagnose failures. If more than one error code is displayed, begin the diagnosis with the first error code. The cause of the first error code can result in false error codes being displayed. If no error code is displayed, see if the error symptom is listed in the Symptom-to-FRU Index.

How to Diagnose Multiple FRUs

When the adapter or device has more than one FRU, the error code could be caused by either FRU. Before replacing multi-FRUs, try removing or exchanging each FRU, one by one in the designated sequence, to see if the symptoms change.

Passwords

The Passwords are security features that are used to protect the system and the hard disk data from unauthorized access. There are three types of passwords as follows:

• Power-on Password (POP)
• Hard disk Password (HDP)
• Supervisor Password (Privileged Access Password, PAP)

No overriding is provided. Obtaining permission from the password owner to unlock the password is a prerequisite for running diagnostic tests and performing maintenance service.

See Password Combinations for more information about passwords.

How to Disable the Power-On Password

Reset Pushbutton

The reset pushbutton resets the system regardless of the microcode status and forces power to be powered-off. Use this pushbutton to power-off when power is not completely off or the microcode is in a hung state. See System Board (Top View) for the location of the pushbutton.

Start here when a ThinkPad 370C, 750 or 755 has a fault: confirm the symptom, then use the table to find the procedure that applies.

This section provides information about the following:

• Memory Checkout
• System Board and Processor Checkout (370C, 750Ce, 755C, 755Cs)
• Keyboard / Auxiliary Input Device Checkout
• TrackPoint II Checkout
• Pen and Digitizer Checkout (360P, 360PE, 750P)
• Audio Card Checkout
• Diskette Drive Test
• Power Systems Checkout
• Power Management Features

Use the following procedure as a guide for computer problems.

Note: The diagnostic tests are intended to test only IBM products. Non-IBM products, prototype cards, or modified options can give false errors and invalid system responses.

1. Obtain the failing symptoms in as much detail as possible.
2. Verify the symptoms by attempting to recreate the failure by running the diagnostic test or by repeating the same operation.

   Note: To run the diagnostics, refer to How to Run the Diagnostics.

3. Use the following table with the verified symptom to determine which page to go to. Search the symptoms column and find the description that best matches your symptom; then go to the page shown in the Go to column.

• External Diskette Drive Test
• External Display Self-Test
• External Keyboard/Auxiliary Input Device Checkout
• Fax/Modem Checkout
• Printer Checkout
• Port Replicator Checkout
• TrackPoint II Checkout
• TV Tuner

External Diskette Drive Test

Use the following procedure to isolate the diskette problem to a controller, drive or diskette. A scratch, write-enabled 2HD diskette is required.

1. Select the icon FDD on the TEST MENU. By doing this, the controller test and the drive read/write test run. If the controller test detects an error, FRU code 10 appears. In this case, replace the system board.
2. If the controller test run without errors, follow the instructions on the screen and insert a scratch diskette.
3. If the drive test detects an error, FRU code 50 appears. If the diskette media are known to be good, replace the drive or the drive cable.

External Display Self-Test

If the display problem occurs only when using an external display, use the following instructions to correct the problem.

If the screen is rolling, replace the display assembly. If that does not correct the problem, replace FRUs in the following order until the problem goes away:

1. Video card
2. Display adapter (any type)
3. System board
4. Bus adapter (if used)

If the screen is not rolling, run the display self-test as follows:

1. Power-off the computer and display.
2. Disconnect the display signal cable.
3. Power-on the display.
4. Set the contrast to its maximum position.
5. Set the brightness control to the center detent position.

Check for the following conditions:

• You should be able to vary the screen intensity by adjusting the contrast and brightness controls.
• The screen should be white or light gray, with a black margin (test margin) on the screen.

  Note: The location of the test margin varies with the type of display. The test margin might be on the top, bottom, or one or both sides.

If you do not see a test margin on the screen, replace the display. If there is a test margin on the screen, replace the system board.

External Keyboard/Auxiliary Input Device Checkout

The following auxiliary input devices may be available for IBM ThinkPad models.

• Numeric keypad
• Mouse (PS/2 compatible)
• External keyboard (with Keyboard/Miniature Mouse cable)

• If you suspect a problem with any of the auxiliary input devices (listed above), replace the device.

  If the problem is not corrected, replace the following FRUs one at a time to correct the problem.

  • Keyboard control card
  • System board
• If the computer receives an incorrect keyboard response, remove other external devices, check the keyboard connections, and recheck the keyboard responses. If the problem remains, replace the following FRUs one at a time to correct the problem.
  • Keyboard
  • Keyboard control card
  • System board
• If a 00030100 error message appears, power-off the computer and the external devices. Then power-on the computer before you power-on the external devices.

Fax/Modem Checkout

Printer Checkout

1. Make sure the printer is correctly connected and is powered-on.
2. Run the printer self-test.

If the printer self-test does not run correctly, the problem is in the printer. Refer to the printer service manual.

If the printer self-test runs correctly, do the following.

1. Verify the port settings in configuration.
2. Install a wrap plug on the port (indicated in configuration) and run the advanced diagnostic tests.
3. If the advanced diagnostic tests (with the wrap plug installed) do not detect a failure, replace the printer cable.

   If the problem is not corrected, replace the system board.

Use the following procedure to isolate a port replicator problem. A port replicator attaches to the system expansion connector at the rear of the computer.

1. Power-off the computer.
2. Remove the failing devices from the replicator.
3. Unplug the AC adapter from the replicator, if attached.
4. Remove the port replicator from the computer.
5. Reconnect the failing device directly to the computer. (If another device occupies the connector, remove it first.)
6. Go to General Checkout and follow that procedure.
7. If the advanced diagnostic device test does not find an error, suspect a problem with the port replicator or the system expansion bus.
8. Power-off the computer and reconnect the port replicator.
9. Power-on the computer and run the following advanced diagnostic tests:
   • Serial port test with the wrap plug installed on the replicator.
   • Parallel port test with the wrap plug installed on the replicator.
   • PCMCIA-2 test with the PC test card installed.
   • FDD-2 (FDD-1 if no drive is installed in the computer) drive test on the failing device.
10. If diagnostic errors appear, replace the replicator or diskette drive attachment unit. If the problem remains after the replacement, replace the system board.
11. If power problems appear only when using the replicator, replace the replicator.

If power shut downs occur intermittently when using PCMCIA-2 devices via a port replicator, suspect an over-current problem. Some PCMCIA devices use more power; if the maximum usage of each device occurs simultaneously, the total current will exceed the limit, thereby causing a power shut down. Isolate this problem by removing one of the devices, and use the computer under the same condition, and see whether a power shut down occurs. Do this procedure for all devices then determine the cause.

Customer purchase of the larger AC adapter (50W, optional) is recommended, if it is not yet in use.

The TV Tuner Pack (hereafter called TV Tuner) is an option for watching TV programs or videos on the IBM TFT color notebook computer. The computer changes to TV reception when the removable diskette drive is replaced with the TV Tuner.

The TV screen and normal computer display are easily switched by using the Hot key on the front panel of the TV Tuner.

Identifying Names and Functions

The following figure and table show the names and functions of each part of the TV Tuner.

Using the Front Panel

The following table shows how to operate all functions of the TV Tuner with the controls on the front panel.

Using the Function Key

Each time you press the Function key (), one of the following messages (called On-Screen Message) appears at the top left corner of the LCD.

The changed values are automatically saved when you return to the “TV Channel” On-Screen message. The values are not saved when you power-off the TV Tuner without returning to this message.

Power-on the TV Tuner

Use the ThinkPad Features program or PS2.EXE. to power-on the TV Tuner; then power-on the internal device in the diskette drive compartment.

Warning: If power for the internal device is turned off when the TV Tuner is set up, nothing appears on the LCD display. Turn on power for the TV Tuner again.

• If you are using DOS, do one of the following:
  • Power-on the computer and type PS2 from the command prompt to start the ThinkPad Features program.

    Select Set Power Features from the ThinkPad Features menu; then put a check mark at Internal Serial Port (or Diskette Drive Compartment) under the Power for devices. If you need help, press F1 to display the help menu.

  • Type PS2 MODEM ON (or PS2 DDC ON) from the command prompt; press the Enter key to set the power ON.
• If you are using OS/2 or Microsoft Windows, do the following:
  1. Power-on the computer and start the ThinkPad Features program.
  2. Select the Power icon; then move the pointer to Internal Serial Port (or Diskette Drive Compartment) under the Power for devices and click the button to check mark it.
  3. Press the OK button.

Troubleshooting

The following table shows what to do to solve problems when the TV Tuner does not work correctly.

Depending on the model, the memory size that is available for customer use appears differently. This is not a hardware problem. See the following table for the available memory size of each card.

Note: For Models 370C, 755C and 755Cs, one of two types of memory cards can be used, IC DRAM card or DIMM card. If DIMM cards are installed, replace IC DRAM with DIMM in the following.

Memory errors might stop system operations, show error messages on the screen, or hang the system. The computer detects memory parity errors but does not correct them.

Use the following procedure to isolate memory problems.

1. Installing a non-parity memory card causes memory errors. Before you go to the next procedure, check whether or not the memory card use parity or non-parity. If the non-parity memory card is installed, disable the parity check on Easy-Setup configuration screen.
2. Make sure that the memory card is fully installed into the connector. Loose connection can cause an error.
3. Power-off the computer and remove the IC DRAM card, or DIMM card from its slot (if installed).
4. Press and hold the F1 key; then power-on the computer. Hold the F1 key down until Easy-Setup screen appears.
5. Select Test and press Enter.
6. Select Memory and press Enter to run the memory test on base memory. If an error appears, replace the system board.
7. Power-off the computer and reinstall the IC DRAM card; then power-on the computer. Verify the memory size; then test the memory. If an error appears, replace the IC DRAM card.

If memory problems occur intermittently, use the loop option to repeat the test. When the test detects an error, an error log is printed on the printer connected to the parallel port. See Error Log for more information.

If a parity error is logged in CMOS, POST error code 118 appears when the power is turned on. To clear the log and to test the memory, run the memory diagnostic. If no error is detected by the test, the log is cleared, and error code 118 will not appear the next time the POST is run. If the 118 error code occurs repeatedly, determine and replace the failing memory FRU. FRUs should not be replaced because of a single, un-reproducible failure. Single failures can occur from a variety of reasons that have nothing to do with a hardware defect such as: cosmic radiation, electrostatic discharge, or software errors. FRUs replacement should only be considered when a recurring problems exits. If this is suspected, clear the error log and run the test again. Do not replace any FRUs if log errors do not reappear.

System Programs in Flash Memory

System setup programs and diagnostic tests are stored in Flash memory.

Flash Memory Update

A flash memory update is required for the following conditions:

• New versions of system programs.
• New feature or options are added.

To update the Flash memory, perform the following steps:

1. Connect the AC Adapter and install the battery pack.
2. Get the appropriate diskette which contains the update.
3. Insert the System Program Service Diskette into drive A and power-on the computer.
4. Select Update system programs from the menu.

The processing functions for the Models 370C, 750C, 755Ce, and 755Cs are performed by both the system board and the processor card. Processor problems can be caused by either FRU. However, the processor card generally has a lower probability of failure. When a numeric code calls the system board or the processor card as a FRU, or the processor card is called by a diagnostic test by showing FRU code 11, use the following procedure to isolate the problem.

1. Run the system board test to verify the symptom. This test verifies both the system board and the processor card. If no error is detected, return to General Checkout.
2. If FRU code 10 appears, replace the system board but do not replace the processor card. Transfer the processor card from the old system board to the new system board.
3. If FRU code 11 appears, reseat the processor card.
4. Rerun the test to verify the fix.
5. If FRU code 11 remains, replace the processor card.

If above procedure does not correct the problem, go to Undetermined Problems.

Remove the external keyboard if the internal keyboard is to be tested.

If the internal keyboard does not work or an unexpected character appears, make sure that the three flexible cables extending from the keyboard are correctly seated in the connectors on the interposer card.

If the keyboard cable connection is correct, run the Keyboard Test by doing the following:

1. Go to diagnostic menu screen by pressing Ctrl+A in Easy-Setup screen.
2. Press Ctrl+K; the figure of the keyboard appears on the screen.
3. Check that when each key is pressed, the key position on the keyboard layout on the screen changes to be a black square.

Note: When a Fn key is pressed, the black square briefly appears.

If the tests detect a keyboard problem, do the following one at a time to correct the problem. Do not replace a non-defective FRU.

• Reseat the three cables.
• Replace the keyboard.
• Replace the interposer card.
• Replace the system board.

The following auxiliary input devices are supported for this computer.

• Numeric keypad
• Mouse (PS/2 compatible)
• External keyboard (with keyboard/mouse cable)

If any of the above devices do not work, reseat the cable connector and repeat the failing operation.

If the problem does not occur again, recheck the connector.

If the problem is not corrected, replace the device, and then the system board.

If the TrackPoint II will not work, check the configuration in Easy-Setup by selecting Keyboard from the Config menu.

If the configuration of the TrackPoint II disabled, select TrackPoint to enable it.

If this does not correct the TrackPoint II problem, continue with the following.

The TrackPoint II does automatic compensations to adjust the pointer sensor. During this process, the pointer moves on the screen automatically for a short time. This self-acting pointer movement can occur when a slight, steady pressure is applied to the TrackPoint II pointer while the computer is powered on or while the system is running, or re-adjustment is required because the temperature has exceeded its normal temperature range. This symptom does not indicate a hardware problem. No service actions are necessary if the pointer movement stops in a short period of time.

If a click button problem or pointing stick problem occurs, do the following:

1. Go to Easy-Setup screen.
2. Select an item with the pointing stick.
3. Press either the left or right click button.
4. Verify that both buttons work correctly.

If either the pointing stick or the click button will not work, do the following actions one at a time to correct the problem. Do not replace a non-defective FRU.

• Reseat the three keyboard cables.
• Replace the keyboard.
• Replace the interposer card.
• Replace the system board.

To check the stylus pen and digitizer, do the following.

1. Press and hold the F1 key.
2. Power-on the computer to go to Easy-Setup screen.
3. Select Test by using the stylus pen.
4. If the test menu appears, the pen and digitizer are operating correctly.

   If the menu does not appear, do the following.

   1. Do the Digitizer Adjustment.
   2. If the problem remains, replace the stylus pen.
   3. If the problem still remains after step 6 in the adjustment, replace the LCD assembly.

Digitizer Adjustment

Adjust the pen-point pressure when:

• The LCD is replaced with a new one.
• The LCD is changed to a pen LCD from a monochrome model.
• The stylus pen or digitizer is not working correctly.

Do the following:

1. Press and hold the F1 key, then power-on the computer to go to the Easy-Setup menu.
2. Press Ctrl+P. The following Pen icon appears on the screen.
3. Open the LCD all the way to 180 degrees. (Do not convert it into the tablet-style notebook.)
4. Select the pen icon by moving the cursor on the icon and clicking it.
5. Without applying any pressure on the screen, hold the stylus pen so it stands on the screen, then press Enter.

   Note: The pressure on the screen should only be from the weight of the stylus pen.

6. Restart the system.

Do the following to run the audio tests.

Note: Refer to Product Overview to see whether the audio card is standard or not.

1. Power-off the computer.
2. Insert the ThinkPad 750Ce hardware maintenance diskette into diskette drive A and power-on the computer.

   Note: You can use this maintenance diskette for all Models.

3. Select the Audio Diagnostics from the main menu.
4. Select Tests from the menu bar and press Enter.
5. Select All tests from the pull-down menu and press Enter.

   Run options are set to test once and stop on error as defaults. Other options can be selected by the pull-down menu of Setting-up.

6. Follow the instructions that appear on the screen to proceed with the tests.
7. If the tests end and no errors are detected, the All tests passed OK message appears.
8. If an error is detected, the FRU code and error description message appear. Go to FRU Codes and replace the FRU.
9. To exit from the test screen, press Esc.

Do the following to isolate the problem to a controller, drive, or diskette. A scratch, write enabled, non-defective 2HD diskette is required.

Warning: Make sure that the diskette does not have more than one label attached to it. Multiple labels can cause damage to the drive or can cause the drive to fail.

1. Do the following to select the test device:
   1. Select the advanced diagnostic mode and select Tool;
   2. Select the icon FDD-1 or FDD-2 and press the space key.

   A √ mark appears next to the selected icon. Insert the blank diskette when instructed.

2. Run the diskette drive test.
3. If the controller test detects an error, FRU code 10 appears. Replace the system board.
4. If the controller test runs without errors, the drive read/write tests start automatically.
5. If the drive test detects an error, FRU code 50 for FDD-1 or 51 for FDD-2 appears. If the diskette itself is known to be good, replace the drive.
6. If the drive is attached through a Port Replicator as FDD-1 or FDD-2 and the test detects errors, move the drive to the computer's diskette drive connector directly, and test it again as FDD-1.

   If no errors occur at the FDD-1 position, the drive is not defective. Go to Port Replicator Checkout in Common Devices Checkout section to isolate the replicator problem.

7. If the drive is attached through an Expansion Unit, go to the service manual of the Expansion Unit to isolate the problem.
8. If the drive is attached through a Diskette Drive Attachment Unit, replace the unit.

If a device is installed but the icon appears in a gray shade rather than a dark shade on the basic diagnostics screen, the device is defective. Reseat the device connectors. If the symptom remains, replace the device or the system board. If needed, adjust the contrast control to clearly distinguish the shades of the icon.

If a device that is not installed appears in a dark shade, for example, FDD-2 appears in a dark shade when NO second FDD is installed, do the following.

1. Replace the first device, such as a FDD-1, HDD-1, or PCMCIA-1.
2. If the problem remains, replace the system board.

PCMCIA-1, Parallel, and Serial icons are always displayed in dark shade, because the icons represent subsystems of the system board and not attachment of the devices.

The HDD-1, FDD-1, or PCMCIA-1 represents the first drive in the system configuration, respectively. Similarly, the HDD-2, FDD-2, or PCMCIA-2 represents the second drive, usually attached through a port replicator or an expansion unit.

To verify the symptom of the problem, power-on the computer using each of the power sources available as follows.

1. Remove the battery pack, diskette drive, and hard disk drive.
2. Connect the AC Adapter and check that power is supplied.
3. Install the diskette drive, or hard disk drive one at a time and check that power is supplied from each power source.
4. Disconnect the AC Adapter, remove the hard disk and diskette drive, and install the charged battery pack; then check that power is supplied by battery pack.

If you suspect a power problem, see the appropriate power supply check listed below.

• Checking the AC Adapter
• Checking Operational Charging
• Checking the Battery Pack
• Checking the Car-Battery Adapter
• Checking the Quick Charger
• Checking the Backup Battery
• Checking the Standby Battery
• Port Replicator Power Overload

Three power management modes are provided by the computer to save power consumption and prolong battery power.

Standby Mode

When in standby mode the following occurs:

• The LCD backlight turns off.
• The hard disk motor stops.
• The CPU clock is set to the lowest speed.

Events that cause entering of standby mode:

• Standby requested by the Fn key. (Fn+F3)
• No activity under auto-standby enabled by the feature utility.

Events that cause exiting or resuming of standby mode:

• (Resume) Any key operation.

Suspend Mode

When in suspend mode, the following, in addition to the four actions of standby mode, occur:

• The LCD power is powered-off.
• The hard disk is powered-off.
• The CPU is stopped.

In the ThinkPad Features Program, the computer can be set to “Will not suspend even if LCD is closed.”

When the computer is powered with ac power and is used with one of the following IBM PC cards, the computer enters standby mode; the PC card and application program remain active.

• 3270 Emulation Credit Card Adapter
• 5250 Emulation Credit Card Adapter
• Token-Ring 16/4 Credit Card Adapter
• Credit Card Adapter for Ethernet

In the following condition, the computer cannot enter the suspend mode.

• While the communication link is running.
• When a serial mouse or other pointing device is selected in the Config menu of Easy-Setup.

Events that cause entering of suspend mode:

• Suspend mode is requested by the Fn key (Fn+F4).
• The LCD is closed.
• The keyboard is opened.
• The specified time has elapsed from the last operation with the keyboard, mouse, hard disk drive, parallel connector, diskette drive, or the AC Adapter is plugged in. The time is specified by Suspend Timer in the ThinkPad Features program.
• The battery condition is low. The battery power indicator blinks (orange).
• The PS2 OFF command is set in the ThinkPad Features program.

Events that cause exiting or resuming of suspend mode:

• (Resume) The LCD is opened.
• (Resume) The keyboard is closed.
• (Resume) Real time clock alarm signaled.
• (Resume) Ring indicator (RI) signaled by serial or PCMCIA device.
• (Resume) The Fn key is pressed.
• (Exit) Timer conditions are satisfied to enter hibernation mode.

Hibernation Mode

When in hibernation mode, the following occurs:

• The system status, RAM, VRAM, and setup data are stored on the hard disk.
• The system is powered-off.

The computer cannot enter hibernation mode when:

• A serial mouse or other pointing device is selected in the Config menu.
• The computer is powered with ac power and one of the following IBM PC cards is used.
  • PCMCIA Data/FAX Modem
  • High Speed PCMCIA Data/FAX Modem
  • 3270 Emulation Credit Card Adapter
  • 5250 Emulation Credit Card Adapter
  • Token-Ring 16/4 Credit Card Adapter
  • Credit Card Adapter for Ethernet

Events that cause entering of hibernation mode:

• The hibernation mode is requested by the Fn key (Fn+F12).
• Timer conditions are satisfied in suspend mode.
• Critical low battery condition.

Event that causes exiting of hibernation mode.

• The power-on switch is operated.

When power is turned on, the hibernation history of the boot record on the hard disk is recognized and system status is restored from the hard disk to resume operation.

1. Power-off the computer and unplug the AC Adapter from the computer.
2. Open the keyboard, and remove the battery pack and the diskette drive.
3. Remove the backup battery from the system board.
4. Measure the voltage of the backup battery. See the following figure.

   

   Wire	Voltage (V dc)
   Red	+2.5 to +3.7
   Black	Ground

   • If the voltage is correct, replace the system board.
   • If the voltage is not correct, the backup battery has been discharged. Replace the backup battery.
   • If the backup battery discharges quickly after replacement, replace the system board.

Battery charging will not start until the Fuel-Gauge shows that less than 90% of the total power remains; with this condition the battery pack will charge to 100% of its capacity. This protects the battery pack from being over-charged or having a shortened life.

1. Power-off the computer.
2. Remove the battery pack and measure the voltage between battery terminals 1 (+) and 4 (−). See the following figure.

   Note: The following figure shows the battery for the Model 370C, 750x, 755C, and 755Cs. The battery for Models 355x and 360x, do not have the storage switch, but the battery terminals are the same.

   

   Terminal	Voltage (V dc) / Signal
   1	+8.0 to +16.0
   2	Send
   3	Thermal
   4	Ground (−)
   5	R1
   6	Select
   7	R2

   Note: Signal lines, not used in these steps, are used for communication between the system and the battery. The storage switch is used to control the power to the internal microprocessor of the battery. The storage switch should be set to off (0) only when the battery is going to be kept in storage for more than two months.

3. If the voltage is less than +8.0 V dc, the battery pack has been discharged or is defective. Recharge the battery. If the recharging does not work, go to Step 5 to check the charging circuit.

   If the voltage is still less than +8.0 V dc after the recharging, replace the battery.

4. If the voltage is more than +8.0 V dc, measure the resistance between battery terminals 3 and 4. The resistance must be 4 to 30 kilohms.

   If the resistance is not correct, replace the battery pack.

   If the resistance is correct, replace the DC/DC card.

5. To check the charging circuit, do the following. Plug in the AC Adapter with the battery pack removed, then power-on the computer.
6. Measure the charging voltage between DC/DC terminals 1 (+) and 4 (−).
7. If the voltage is less then +9.0 V dc, replace the DC/DC card. If the voltage is more than +9.0 V dc, the charging circuit is working correctly, replace the battery pack.

You are here because the computer fails only when the AC Adapter is used.

• If the power problem occurs only when the port replicator is used, replace the replicator.
• If the power-on indicator does not turn on, check the power cord of the AC Adapter for correct continuity and installation.
• If the operational charge does not work, go to Checking Operational Charging.

Note: There are two types of adapters. The procedure for checking both types is the same.

1. Unplug the AC Adapter cable from the computer and measure the output voltage at the plug of the AC Adapter cable. See the following figure.

   

   Pin	Voltage (V dc)
   1	+19.0 to +21.0
   2	Ground

   • If the voltage is correct, replace the system board. If the problem is not corrected, go to Undetermined Problems.
   • If the voltage is not correct, go to the next step.
2. Unplug the AC Adapter cable from the ac power outlet and wait five minutes or longer to allow the over voltage protection circuit to be fully discharged and initialized.
3. Plug the AC Adapter cable into the ac power outlet.
4. Measure the output voltage of the AC Adapter.
5. If the voltage is still not correct, replace the AC Adapter.

Note: An audible noise from the AC Adapter does not always indicate a defective adapter.

To check operational charging, use a discharged battery pack or a battery pack that shows a yellow or orange battery status indicator when it installed in the computer.

Perform operational charging. If the battery status indicator turns orange and the battery charging indicator turns green within two minutes, replace the AC Adapter.

There are two types of adapters but the checkout procedure is the same for both of them.

1. Unplug the Car-Battery Adapter cable from the computer.
2. Plug the Car-Battery Adapter into the cigarette lighter socket.

   Note: If the adapter is already plugged in, reseat it.

3. Measure the output voltage of the Car-Battery Adapter cable. See the following figure.

   

   Pin	Voltage (V dc)
   1	+19.0 to +21.0
   2	Ground

   • If the voltage is correct and the power-on indicator on the Car-Battery Adapter is on all the time, the Car-Battery is working correctly. Replace the system board.

     If the problem is not resolved when the system board is replaced, go to Undetermined Problems.

   • If the voltage is outside the normal voltage range, do one of the following:
     • Try the above test procedures in a different car, if one is available.
     • Replace the Car-Battery Adapter if the computer works correctly with the AC Adapter.

There are two types of chargers, but checkout procedures are the same for both of them.

1. Ensure that the battery pack is operating correctly. (See Checking the Battery Pack.)
2. Connect the power cord to the quick charger and the other end to an ac power outlet. Ensure that the power-on indicator is on.
   • If the power-on indicator does not turn on, check the power cord for correct continuity and installation.
   • If the problem is not corrected, replace the quick charger or the power cord.
3. Install the battery pack into the quick charger.
   • If the charging indicator does not start blinking, replace the quick charger.

1. Power-off the computer and unplug the AC Adapter from the computer.
2. Open the keyboard, and remove the battery pack and the diskette drive.
3. Remove the standby battery.
4. Measure the voltage of the standby battery.
   • If the voltage between red and black is 3.5 V dc or greater, the voltage is correct. Go to Step 10 to verify standby battery operation.
   • If the voltage is less than 3.5 V dc, go to the next step.
5. Plug the AC Adapter into the computer and power-on the computer.
6. Measure the output voltage at the connector on the system board.

   

   Pin	Voltage (V dc)
   +	+4.0
   −	Ground

   • If the voltage is less than +4.0 V dc, replace the DC/DC card. If the voltage is still low, replace the system board.
   • If the voltage is more than +4.0 V dc, power-off the computer, replace the standby battery, and go to the next step.
7. Ensure that the AC Adapter is plugged into the computer; then power-on the computer.
8. Charging of the standby battery starts. A depleted battery needs approximately 30 minutes to be recharged to the operational voltage of +3.5 V dc.
9. Unplug the AC Adapter.
10. Verify the standby battery function by removing and installing the battery pack during suspend mode.

    Note: Removing and installing the battery pack during suspend mode should be done within one minute. The resume operation must start. If the resume operation does not work, switching of power from the battery pack to standby battery will not be correct. Replace the DC/DC card.

    If replacing the DC/DC card does not resolve the problem, replace the system board.

If power shut downs occur intermittently when using PCMCIA-2 devices via a port replicator, suspect an over-current problem. Some PCMCIA devices use more power; if the maximum usage of each device occurs simultaneously, the total current will exceed the limit, thereby causing a power shut down. Isolate this problem by removing one of the devices, and use the computer under the same condition to see whether a power shut down occurs. Do this procedure for all devices, then determine the cause. Use of the larger AC Adapter (50W, optional) is recommended, if one is not yet in use.

The system status indicators show the current computer status in different colors (green, yellow, and orange).

Use either the TrackPoint II or the cursor move keys to interact with the tests. The Enter key works the same as selecting the OK icon to reply OK.

1. Press and hold the F1 key; then power-on the computer. Hold the F1 key down until Easy-setup screen appears.
2. Select Test and press Enter.
3. Select a device and press Enter to run the test.
4. The test progress screen appears.
5. OK appears when the test ends without any errors.
6. Start the Advanced Diagnostic test by pressing Ctrl+A on the basic diagnostic menu screen.
7. Select Tool to install the tools.
8. Select a device, press the space key, and install the tool. Multiple devices can be selected by repeating this step.

   A √ mark appears for the selected device.

9. Select OK and press Enter if the selection is OK.
10. Select a device and press Enter to start the tests.
11. Select Test All to test all devices.
12. Select Loop Test to loop tests.

    A loop option menu appears in which a device loop or all loop can be selected. Select a device and press the space key to select a device. Repeat this step to select multiple devices. Press Enter to start the diagnostic loop. If no device is selected, all device tests are looped.

13. To exit the loop, keep pressing Ctrl+Pause until the test exits. A beep sounds (750Ce, 755C, 755Cs) to notify that the exit interrupt is sensed by the test program.

The password relationship is:

When POP is the same as HDP

The POP prompt appears, but the HDP prompt does not appear.

When POP is not the same as HDP

Both POP and HDP prompts appear.

PAP and HDP

When PAP is used, the HDP is enabled automatically, but no HDP prompt appears. The HDP is set the same as PAP.

Do the following to format the hard disk.

Warning: Make sure the drive address to be formatted is correct. This procedure will erase all information on the disk.

1. Power-off the computer.
2. Insert the ThinkPad 750Ce hardware maintenance diskette into diskette drive A and power-on the computer.

   Note: You can use this maintenance diskette for all Models.

3. Select Format the hard disk from the main menu.
4. Select the drive from the menu.
5. Follow the instructions on the screen.

The green LED on the PC test card turns on when the PCMCIA test is running. If the LED does not turn on, check that the card is installed correctly by reseating the card. If it still does not turn on after it is reseated, try using another slot for the test. If the LED still does not turn on and the test fails, replace the FRU shown in the diagnostic error code.

The following table shows the Fn key and function key combinations and their corresponding functions.

The Fn key works independently from the operating system. The operating system obtains the status through the system management interface to control the system.

Do the following to run the keyboard test.

1. Go to the advanced diagnostic screen menu by pressing Ctrl+A in Easy-Setup menu.
2. Go to the keyboard diagnostic test menu by pressing Ctrl+K.
3. Check that when each key is pressed, the key position on the keyboard layout on the screen changes to be a black square.

   Note: When a Fn key is pressed, the black square briefly appears.

This section provides information about the following:

• Numeric Error Codes
• FRU Codes
• Beep Symptoms
• No Beep Symptoms
• LCD Related Symptoms
• Keyboard/TrackPoint II Related Symptoms
• Indicator Related Symptoms
• Power Related Symptoms
• Function/Audio Related Symptoms
• Peripheral Device Related Symptoms
• Other Symptoms
• Intermittent Problems
• Undetermined Problems

The Symptom-to-FRU Index lists the symptoms and errors and the possible causes. The most likely cause is listed first.

Note: Perform the FRU replacement or actions in the sequence shown in the “FRU/Action” columns. If a FRU did not solve the problem, put the original part back in the computer.

This index can also be used to help you decide which FRUs to have available when servicing a computer.

Numeric error codes show the errors detected in POST or system operation. In the following error codes, X can be any number.

If no codes are available, use narrative symptoms.

If the symptom is not listed, go to Undetermined Problems.

If you suspect a problem with the Port Replicator, see Port Replicator Checkout in the Common Devices Checkout section for more information.

The TFT LCD of the notebook computers contain over 921 000 thin film transistors (TFTs). A small number of missing, discolored or lighted dots (on all the time) is characteristic of TFT LCD technology. Excessive pixel problems can cause viewing concerns. The LCD should be replaced if the number of missing or discolored, or lighted dots in any colored background is 21 or more.

Note: If you cannot find a symptom or error in this list and the problem remains, see Undetermined Problems.

You are here because the diagnostic tests did not identify which adapter or device failed, installed devices are incorrect, a short circuit is suspected, or the system is inoperative. Follow the procedures below to isolate the failing FRU (do not isolate non-defective FRUs).

Verify that all attached devices are supported by the computers.

Verify that the power supply being used at the time of the failure is operating correctly. (See Power Systems Checkout.)

1. Power-off the computer.
2. Check the cables, wires, and connectors for short circuits and open circuits. Visually check them for damage. If any problems are found, replace the FRU.
3. Remove or disconnect all of the following devices.
   1. Non-IBM devices
   2. Devices attached to the expansion bus connector
   3. Printer, mouse, and other external devices
   4. Battery pack
   5. Hard disk drive
   6. Diskette drive or the device attached to the diskette drive connector
   7. IC DRAM card or DIMM card
   8. PC cards

   Note: Remember that removing the hard disk drive, an IC DRAM card, or any adapter or device, might cause configuration errors. Ignore error code 174.

4. Power-on the computer.
5. Determine if the problem has changed.
6. If the problem does not occur again, reconnect the removed devices one at a time until you find the failing FRU.
7. If the problem remains, replace the following FRUs one at a time. Do not replace a non-defective FRU.
   • DC/DC card
   • Audio card
   • Interposer card
   • LCD assembly
   • System board
   • Processor card (370C, 750Ce, 755C, and 755Cs)

Diagnostic errors are printed on the printer that is attached to the parallel port when the error is detected. The error is also logged in the system memory.

Do the following procedure to display the errors.

1. End the test, if it is running.
2. Press Ctrl+A to select the advanced diagnostic mode.
3. Press Ctrl+E.
4. The error log appears.
5. To exit the screen, select the cancel icon or press Esc.

The error log is not saved when system power is powered-off.

If an error is detected by the diagnostic tests, a four-digit FRU code is displayed. The FRU code indicates two suspected FRUs. Replace the FRU that is indicated by the two leftmost digits first, then replace the FRU indicated by the two rightmost digits. No FRU is assigned to code 00. If only one FRU is suspected, the other FRU code is filled with zeros. See the referenced page before replacing the FRU.

Note: The device ID and error codes are used to indicate the detail portion of the FRU which caused the error. If replacing a FRU does not correct a problem, see the Device ID or error code from the previous failure. If they have changed, the cause might be because the new FRU is defective or that the FRU was incorrectly installed.

If the problem remains after replacement of the FRUs, go to Undetermined Problems.

Intermittent system hang problems can be caused by a variety of reasons that have nothing to do with a hardware defect such as: cosmic radiation, electrostatic discharge, or software errors. FRUs replacement should only be considered when a recurring problems exits.

When analyzing the intermittent problem, do the following:

1. Run the advanced diagnostic test for the system board in loop mode at least 10 times.
2. If no error is detected, do not replace any FRUs.
3. If any error is detected, replace the FRU shown by the FRU code. Rerun the test to verify that no more errors exist.

• Removals - Models 355x, 360x
• Removals - Models 370C, 750x, 755C, 755Cs

This section contains information about removals and replacements.

• The system board is sensitive to, and can be damaged by, electrostatic discharge. Establish personal grounding by touching a ground point with one hand before touching these units.

  An electrostatic discharge (ESD) strap must be used to establish personal grounding.

• Do not damage any part. Only certified trained personnel should service the computer.
• The arrows in the “Removals and Replacements” section show the direction of movement to remove a FRU, or to turn a screw to release the FRU. The arrows are marked in numeric order, in square callouts, to show the correct sequence of removal.
• When other FRUs must be removed before removing the failing FRU, they are listed at the top of the page.
• To replace a FRU, reverse the removal procedure and follow any notes that pertain to replacement. See Locations for internal cable connections and arrangement information.
• When replacing a FRU, use the correct screw size as shown in the procedures.

• 1010 Rear Connector Door
• 1015 Foot
• 1020 Battery Pack
• 1030 Diskette Drive
• 1035 Hard Disk Drive
• 1040 Keyboard Unit
• 1050 IC DRAM Card
• 1055 Diskette Drive Bezel
• 1060 Status Indicator
• 1070 LCD Assembly
• 1080 Modem Card (355x)
• 1085 Bezel (360x)
• 1090 Speaker Shield Assembly
• 1095 Interposer Card
• 1100 DC/DC Card
• 1110 Backup Battery
• 1115 Standby Battery
• 1120 System Board Assembly
• 1130 PCMCIA Slot Assembly

• 2010 Rear Connector Door
• 2015 Foot
• 2020 Battery Pack
• 2030 Diskette Drive
• 2035 Hard Disk Drive
• 2040 Keyboard Unit
• 2050 IC DRAM Card
• 2055 DIMM and DIMM Adapter (755C, 755Cs)
• 2056 Diskette Drive Bezel
• 2060 Status Indicator
• 2070 LCD Assembly
• 2080 Speaker Shield Assembly
• 2085 Audio Card
• 2090 Interposer Card
• 2100 DC/DC Card
• 2110 Backup Battery
• 2105 Standby Battery
• 2120 System Board Assembly
• 2130 PCMCIA Slot Assembly
• 2140 Processor Card (750Ce, 755C, 755Cs)

• Battery Pack (2020)
• Keyboard Unit (2040)
• Status Indicator (2060)

1. When replacing the LCD ground-terminal screw, do not pull or push the LCD cables.
2. When removing the LCD cables, pull the connector straight up. Incorrect handling can damage the connector.

   Note: For the color models, make sure the indicator does not catch the right LCD connector when replacing the status indicator.

3. Remove the screw.
4. Remove the right hinge cover.
5. When removing the left hinge cover, use a small screwdriver as shown to release the latch from the rear base cover. Pull the hinge cover slightly upward to keep it unlatched.
6. From the front side, remove the latch with a small screwdriver as shown to remove the cover. Be careful not to scratch the surface of the computer when you use a screwdriver to remove the latches.
7. Remove the four screws.

Use the following table for reference when replacing parts.

Note: Make sure you use the correct screw. See Screw Size Chart.

Use the chart to match the size and shape of the screws in the computer you are servicing.

Remove the center latch 1; then remove the rear connector door by flexing it 2.

To replace the foot:

• Align the foot in the open position with one pivot in its hinge in the base cover
• Press the other pivot point into position with your thumb or finger

• Battery Pack (1020)

After replacing the diskette drive, latch the removal strap into the correct position.

• Battery Pack (1020)

After replacing the hard disk drive, latch the removal strap into the correct position.

• Battery Pack (1020)

1. When removing the screw covers, use a small screwdriver as shown.

2. Warning: When using a screwdriver to remove cover or latches, be careful not to:

   • Scratch the surface of the computer.
   • Break the latches.
3. Open the keyboard.
4. Remove the leaf-spring plate.
5. When unlatching the upper cover latches to remove the upper cover, use a small screwdriver as shown.

6. Remove the upper cover.

   Note: To remove the upper cover, do not latch the keyboard. Lower the keyboard and remove the upper cover.

7. Disconnect the cables to remove the keyboard unit as shown.

   Warning: Do not pull the keyboard cables. The keyboard cables can be damaged if the keyboard is disconnected without releasing the three latches 7.

8. Remove the keyboard.

Use the following table for reference when replacing parts.

Note: Make sure you use the correct screw. See Screw Size Chart.

Notes for when replacing

1. When replacing the keyboard, check that the three cables are clean, and inserted straight and fully into the connectors. Slide both ends of each latch at the same time to make sure that each cable is correctly inserted.

   Warning: While pressing the cables into place, be careful not to break the flexible cables.

   Go to Keyboard/Auxiliary Input Device Checkout and test all keys before returning the computer to the customer.

2. When replacing the upper cover, insert the two latches located on the rear side of the cover into the guide of the LCD foot; then push the right, left, and front sides to snap them into place. Be careful not to damage the suspend/resume switch when putting on the cover.

• Battery Pack (1020)
• Diskette Drive (1030)

Warning: The IC DRAM card is sensitive to physical shock. Incorrect handling of the card can damage it. The eject tape (P/N 53G9318) must be used to remove the card.

• Battery Pack (1020)
• Diskette Drive (1030)

Insert a coin between the diskette drive bezel and the computer as shown 1 and push the bezel from the bottom of the computer 2 to remove it.

• Battery Pack (1020)
• Keyboard Unit (1040)
• Status Indicator (1060)

1. When replacing the LCD ground-terminal screw, do not pull or push the LCD cables.
2. When removing the LCD cables, pull the connector straight up. Incorrect handling can damage the connector.

   Note: For the color model, make sure the indicator does not hook the most right LCD connector when replacing the status indicator.

3. Remove the screw.
4. Remove the right hinge cover.
5. When removing the left hinge cover, use a small screwdriver as shown to release the latch from the rear base cover. Pull the hinge cover slightly upward to keep it unlatched.
6. From the front side, remove the latch with a small screwdriver as shown to remove the cover. Be careful not to scratch the surface of the computer when you use a screwdriver to remove the latches.
7. Remove the four screws.

Use the following table for reference when replacing parts.

Note: Make sure you use the correct screw. See Screw Size Chart.

1095 Interposer Card

• Battery Pack (1020)
• Diskette Drive (1030)
• Hard Disk Drive (1035)
• Keyboard Unit (1040)
• Status Indicator (1060)
• LCD Assembly (1070)
• Modem Card (1080)

Warning: Carefully remove any metal particles that might have flaked off. Be careful not to damage it with a screwdrivers, screws, or other objects.

2. When replacing the speaker shield, insert it under the projection at the left, rear corner of the computer base.

   Note: The shaded part in the figure is attached to the speaker shield assembly with light adhesive. This is a separate FRU from the speaker shield assembly.

3. When raising the speaker shield assembly, make sure that the shield assembly does not hook the three flexible cables of the keyboard.

   For Model 360, gently raise the speaker shield assembly to avoid damaging the speaker cable. (For Models 355 and 355Cs, skip step 3; the speaker cable has already been removed.)

Use the following table for reference when replacing parts.

Note: Make sure you use the correct screw. See Screw Size Chart.

• Battery Pack (1020)
• Diskette Drive (1030)
• Hard Disk Drive (1035)
• Keyboard Unit (1040)
• Status Indicator (1060)
• LCD Assembly (1070)
• Modem Card (1080)
• Speaker Shield Assembly (1090)
• Interposer Card (1095)
• DC/DC Card (1100)
• Backup Battery (1110)
• Standby Battery (1115)

Use the following table for reference when replacing parts.

Note: Make sure you use the correct screw. See Screw Size Chart.

• Battery Pack (1020)
• Diskette Drive (1030)
• Hard Disk Drive (1035)
• Keyboard Unit (1040)
• Status Indicator (1060)
• LCD Assembly (1070)
• Modem Card (1080)
• Speaker Shield Assembly (1090)
• Interposer Card (1095)
• DC/DC Card (1100)
• Backup Battery (1110)
• Standby Battery (1115)
• System Board Assembly (1120)

Warning: The system board can be damaged if the lower shield touches the system board components. Carefully follow the next instruction.

In step 4, gradually raise the system board from the lower shield until all the components of the system board just clear the tabs of the lower shield. Be careful not to raise it too far. While keeping the clearance to a minimum, separate the system board from the lower shield by moving the system board straight forward as shown by step 2.

Use the following table for reference when replacing parts.

Note: Make sure you use the correct screw. See Screw Size Chart.

Remove the center latch 1; then remove the rear connector door by flexing it 2.

To replace the foot:

• Align the foot in the open position with one pivot in its hinge in the base cover
• Press the other pivot point into position with your thumb or finger

• Battery Pack (2020)

After replacing the diskette drive, latch the removal strap into the correct position.

• Battery Pack (2020)

After replacing the hard disk drive, latch the removal strap into the correct position.

• Battery Pack (2020)

1. When removing the screw covers, use a small screwdriver as shown.

2. Warning: When using a screwdriver to remove cover or latches, be careful not to:

   • Scratch the surface of the computer.
   • Break the latches.
3. Open the keyboard.
4. Remove the leaf-spring plate.
5. When unlatching the upper cover latches to remove the upper cover, use a small screwdriver as shown.

6. Remove the upper cover.

   Note: To remove the upper cover, do not latch the keyboard. Lower the keyboard and remove the upper cover.

7. Disconnect the cables to remove the keyboard unit as shown.

   Warning: Do not pull the keyboard cables. The keyboard cables can be damaged if the keyboard is disconnected without releasing the three latches.

8. Remove the keyboard.

Use the following table for reference when replacing parts.

Note: Make sure you use the correct screw. See Screw Size Chart.

Notes for when replacing

1. When replacing the keyboard, check that the three cables are clean, and inserted straight and fully into the connectors. Slide both ends of each latch at the same time to make sure that each cable is correctly inserted. Go to Keyboard/Auxiliary Input Device Checkout and test all keys before returning the computer to the customer.
2. When replacing the upper cover, insert the two latches located rear side of the cover into the guide of the foot of the LCD; push the right, left, and front sides to snap into place. Be careful not to damage the suspend/resume switch when putting on the cover.

• Battery Pack (2020)
• Diskette Drive (2030)

For Models 370C, 755C and 755Cs, one of two types of memory card can be used, IC DRAM card or DIMM card.

Warning: The IC DRAM card is sensitive to physical shock. Incorrect handling of the card can damage it. The eject tape (P/N 53G9318) must be used to remove the card.

• Battery Pack (2020)
• Diskette Drive (2030)

Press both locks at the same time and remove the DIMM.

While holding the strap 1, pull the DIMM adapter toward the front 2 to remove it.

• Battery Pack (2020)
• Diskette Drive (2030)

Insert a coin between the diskette drive bezel and the computer as shown 1 and push the bezel from the bottom of the computer 2 to remove it.

• Battery Pack (2020)
• Diskette Drive (2030)
• Hard Disk Drive (2035)
• Keyboard Unit (2040)
• Status Indicator (2060)
• LCD Assembly (2070)

Models 750x, 755C, and 755Cs and Model 370C

1. Remove the screws.
2. Gently raise the speaker shield assembly to avoid damaging the speaker cable and make sure that the shield assembly does not hook the three flexible cables of the keyboard.
3. Disconnect the speaker connector.

Use the following table for reference when replacing parts.

Note: Make sure you use the correct screw. See Screw Size Chart.

• Battery Pack (2020)
• Diskette Drive (2030)
• Hard Disk Drive (2035)
• Keyboard Unit (2040)
• Status Indicator (2060)
• LCD Assembly (2070)
• Speaker Shield Assembly (2080)
• Audio Card (2085)
• Interposer Card (2090)
• DC/DC Card (2100)
• Backup Battery (2110)
• Standby Battery (2105)

Use the following table for reference when replacing parts.

Note: Make sure you use the correct screw. See Screw Size Chart.

• Battery Pack (2020)
• Diskette Drive (2030)
• Hard Disk Drive (2035)
• Keyboard Unit (2040)
• Status Indicator (2060)
• LCD Assembly (2070)
• Speaker Shield Assembly (2080)
• Audio Card (2085)
• Interposer Card (2090)
• DC/DC Card (2100)
• Backup Battery (2110)
• Standby Battery (2105)
• System Board Assembly (2120)

Use the following table for reference when replacing parts.

Note: Make sure you use the correct screw. See Screw Size Chart.

• Battery Pack (2020)
• Diskette Drive (2030)
• Hard Disk Drive (2035)
• Keyboard Unit (2040)
• Status Indicator (2060)
• LCD Assembly (2070)
• Speaker Shield Assembly (2080)
• Audio Card (2085)
• Interposer Card (2090)
• DC/DC Card (2100)
• Backup Battery (2110)
• Standby Battery (2105)
• System Board Assembly (2120)
• PCMCIA Slot Assembly (2130)

Warning: The system board can be damaged if the lower shield touches the system board components. Carefully follow the next instruction.

In step 3, gradually raise the system board from the lower shield until all components of the system board just clear the tabs of the lower shield. Be careful not to raise it too far. While keeping the clearance to a minimum, separate the system board from the lower shield by moving the system board straight forward as shown by step 3.

Note: In step 1, each screw has a flat washer and a lock washer. When reinstalling the screws, make sure that the lock washer is placed next to the head of the screw. Incorrect washer placement can cause metal to flake.

Turn the system board upside down. Remove the screws 4 and 5. Models 370C, 755C and 755Cs have only the screw on the right side in step 5.

Use the following table for reference when replacing parts.

Note: Make sure you use the correct screw. See Screw Size Chart.

• System - Front View (750, 750Cx, 755Cx, 370C, 360x, 355x)
• System Front View - (750P, 360P, 360PE)
• System Rear View - All Models
• System Board (Top View)
• System Board (Bottom View)
• Processor Card (370C, 750Ce, 755C, 755Cs)
• DC/DC Card - Top View
• Interposer Card - All Models (Front View)

1. LCD
2. Contrast Control

   Note: The Model 360 does not have a contrast control. The Model 755C has one of two types of LCD: one with a contrast control and one without.

3. Brightness Control
4. Status Indicator

   See Status Indicators.

5. External Input Device Connector
6. PCMCIA Slot
7. PCMCIA Release Lever
8. Keyboard
9. LCD and Keyboard Latch
10. TrackPoint II
11. Click Button
12. Diskette-Eject Button
13. Diskette Drive
14. Fn Key

1. Convertible LCD
2. Contrast Control
3. Brightness Control
4. Status Indicator
5. External Input Device Connector
6. PCMCIA Slot
7. PCMCIA Release Lever
8. Keyboard
9. LCD and Keyboard Latch
10. Hard Disk Drive Compartment
11. Battery Compartment
12. Click Buttons
13. Diskette-Eject Button
14. Diskette Drive
15. Fn Key
16. TrackPoint II
17. Stylus Pen

1. Diskette Drive Cover
2. Power Switch
3. Microphone/Line-In Jack
4. Headphone Jack

   Note: Not all models have jacks 3 and 4.

5. Power Jack
6. Serial Connector
7. Parallel Connector
8. External Display Connector
9. Reset Pushbutton
10. System Expansion Connector

    Note: Model 355x does not have this connector.

    A multimedia portable expansion unit, port replicator, or port replicator with PCMCIA can be connected to this interface to support the following features.

    • 16-bit AT-bus interface
    • Serial port
    • Parallel port
    • Keyboard and mouse
    • HDD connection
    • LED control signals
    • Visual signals
    • Audio signals
    • FDD signals
    • PCMCIA signals
    • Power controls
    • Power line
11. Connector Door
12. Rear Door

1. Power Switch
2. Modem Card Connector (355x, 360x)
3. Serial Connector
4. Audio Card Connector
5. Speaker Connector (370C only)
6. Parallel Connector
7. Interposer Card Connector
8. External Display Connector
9. Reset Pushbutton
10. System Expansion Connector

    Note: Model 355x does not have this connector.

11. External Input Device Connector
12. Hard Disk Drive Connector
13. PCMCIA Slot
14. DC/DC Card Connector
15. IC DRAM Card Connector
16. Diskette Drive Connector

1. Power-On Password Connector
2. Backup Battery Connector
3. Standby Battery Connector
4. IC DRAM Card Connector
5. Processor Card Connector (750Ce, 755C, 755Cs)

1. System Board Connector

1. External Power Jack
2. Battery Pack Terminal

1. LCD Connector, Color
2. LCD Connector, Pen
3. LCD Connector, Monochrome and Color
4. LCD Power Connector, Color
5. Status Indicator Connector
6. Keyboard TrackPoint II Connector
7. Keyboard Signal Connector
8. Keyboard Signal Connector
9. LCD Open Detect Switch

This section contains FRUs common to most IBM portable, laptop, and notebook computers.

External Diskette Drives

CD-ROM Drives

SCSI Adapters, Terminators, Cables

Rewritable Optical Drives

External Keyboard/Mouse

Enhanced Keyboards (101/102 Key)

Optional Enhanced Keyboards (101/102 Key)

Keybutton Kits (101/102 Key)

Japanese Keyboard Type 2 (106 Key, DBCS Support)

Space-Saving Keyboards (84/85 Key)

Tools and Miscellaneous

System Unit (355x, 360x)

Keyboard

System Unit (370C)

Keyboard

System Unit (750x)

⁴ See Digitizer Adjustment.

⁵ See Digitizer Adjustment.

Keyboard

System Unit (755C, 755Cs)

⁶ See Digitizer Adjustment.

Keyboard

Miscellaneous Parts

Options

Model Unique Options

Models 355x, 360x, 370C

Model 370C

Model 750x

Model 755C, 755Cs

Numeric Keypad

Accessories

Tools

Power Cords

Warning: Use the power cord certified for your country.

Certaines batteries de secours contiennent du nickel et du cadmium. Ne les démontez pas, ne les rechargez pas, ne les exposez ni au feu ni à l'eau. Ne les mettez pas en court-circuit. Pour les mettre au rebut, conformez-vous à la réglementation en vigueur. Lorsque vous remplacez la pile de sauvegarde ou celle de l'horloge temps réel, veillez à n'utiliser que les modèles cités dans la liste de pièces détachées adéquate. Une batterie ou une pile inappropriée risque de prendre feu ou d'exploser.

Die Bereitschaftsbatterie, die sich unter dem Diskettenlaufwerk befindet, kann geringe Mengen Nickel und Cadmium enthalten. Sie darf nur durch die Verkaufsstelle oder den IBM Kundendienst ausgetauscht werden. Sie darf nicht zerlegt, wiederaufgeladen, kurzgeschlossen, oder Feuer oder Wasser ausgesetzt werden. Die Batterie kann schwere Verbrennungen oder Verätzungen verursachen. Bei der Entsorgung die örtlichen Bestimmungen für Sondermüll beachten. Beim Ersetzen der Bereitschafts- oder Systembatterie nur Batterien des Typs verwenden, der in der Ersatzteilliste aufgeführt ist. Der Einsatz falscher Batterien kann zu Entzündung oder Explosion führen.

Alcune batterie di riserva contengono una piccola quantità di nichel e cadmio. Non smontarle, ricaricarle, gettarle nel fuoco o nell'acqua né cortocircuitarle. Smaltirle secondo la normativa in vigore (DPR 915/82, successive disposizioni e disposizioni locali). Quando si sostituisce la batteria dell'RTC (real time clock) o la batteria di supporto, utilizzare soltanto i tipi inseriti nell'appropriato Catalogo parti. L'impiego di una batteria non adatta potrebbe determinare l'incendio o l'esplosione della batteria stessa.

Algunas baterías de reserva contienen una pequeña cantidad de níquel y cadmio. No las desmonte, ni recargue, ni las eche al fuego o al agua ni las cortocircuite. Deséchelas tal como dispone la normativa local. Utilice sólo baterías que se encuentren en la lista de piezas. La utilización de una batería no apropiada puede provocar la ignición o explosión de la misma.

La pile de sauvegarde contient du lithium. Elle présente des risques d'incendie, d'explosion ou de brûlures graves. Ne la rechargez pas, ne retirez pas son connecteur polarisé et ne la démontez pas. Ne l'exposez pas à une temperature supérieure à 100°C, ne la faites pas brûler et n'en exposez pas le contenu à l'eau. Mettez la pile au rebut conformément à la réglementation en vigueur. Une pile inappropriée risque de prendre feu ou d'exploser.

Die Systembatterie ist eine Lithiumbatterie. Sie kann sich entzünden, explodieren oder schwere Verbrennungen hervorrufen. Batterien dieses Typs dürfen nicht aufgeladen, zerlegt, über 100 C erhitzt oder verbrannt werden. Auch darf ihr Inhalt nicht mit Wasser in Verbindung gebracht oder der zur richtigen Polung angebrachte Verbindungsstecker entfernt werden. Bei der Entsorgung die örtlichen Bestimmungen für Sondermüll beachten. Beim Ersetzen der Batterie nur Batterien des Typs verwenden, der in der Ersatzteilliste aufgeführt ist. Der Einsatz falscher Batterien kann zu Entzündung oder Explosion führen.

La batteria di supporto e una batteria al litio e puo incendiarsi, esplodere o procurare gravi ustioni. Evitare di ricaricarla, smontarne il connettore polarizzato, smontarla, riscaldarla ad una temperatura superiore ai 100 gradi centigradi, incendiarla o gettarla in acqua. Smaltirla secondo la normativa in vigore (DPR 915/82, successive disposizioni e disposizioni locali). L'impiego di una batteria non adatta potrebbe determinare l'incendio o l'esplosione della batteria stessa.

La bateria de repuesto es una bateria de litio y puede provocar incendios, explosiones o quemaduras graves. No la recargue, ni quite el conector polarizado, ni la desmonte, ni caliente por encima de los 100°C (212°F), ni la incinere ni exponga el contenido de sus celdas al agua. Deséchela tal como dispone la normativa local.

Si le panneau d'affichage à cristaux liquides se brise et que vous recevez dans les yeux ou sur les mains une partie du fluide, rincez-les abondamment pendant au moins quinze minutes. Consultez un médecin si des symptômes persistent après le lavage.

Die Leuchtstoffröhre im LCD-Bildschirm enthält Quecksilber. Bei der Entsorgung die örtlichen Bestimmungen für Sondermüll beachten. Der LCD-Bildschirm besteht aus Glas und kann zerbrechen, wenn er unsachgemäß behandelt wird oder der Computer auf den Boden fällt. Wenn der Bildschirm beschädigt ist und die darin befindliche Flüssigkeit in Kontakt mit Haut und Augen gerät, sollten die betroffenen Stellen mindestens 15 Minuten mit Wasser abgespült und bei Beschwerden anschließend ein Arzt aufgesucht werden.

Nel caso che caso l'LCD si dovesse rompere ed il liquido in esso contenuto entrasse in contatto con gli occhi o le mani, lavare immediatamente le parti interessate con acqua corrente per almeno 15 minuti; poi consultare un medico se i sintomi dovessero permanere.

Si la LCD se rompe y el fluido de su interior entra en contacto con sus ojos o sus manos, lave inmediatamente las áreas afectadas con agua durante 15 minutos como mínimo. Obtenga atención medica si se presenta algún síntoma del fluido despues de lavarse.