TP 755CD/CDV - Miscellaneous Symptoms

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Service Hints & Tips

Document ID: GSMH-3BFLHN

TP 755CD/CDV - Miscellaneous Symptoms

Applicable to: World-Wide

LCD Related Symptoms:
The TFT LCD for the notebook computer contains 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, but excessive pixel problems can cause viewing concerns.

Before Replacing the LCD:
The LCD should not be replaced unless the number of dots satisfies the following condition:
The number of missing or discolored, or lighted dots in any colored background is 21 or more.

Note:
For Model 755CDV, see also "Model 755CDV Symptoms" for LCD related symptoms.

Symptom/Error

FRU/Action

No beep, power-on indicator on, and a blank LCD during POST.

1. System Board
2. DC/DC Card
3. Video Card
4. Processor Card

LCD backlight not working, or
LCD too dark, or
LCD brightness cannot be adjusted, or
LCD contrast cannot be adjusted.

1. Reseat the LCD connectors.
2. LCD Assembly
3. Interposer Card
4. DC/DC Card

LCD screen unreadable, or
Characters missing pels, or
Screen abnormal, or
Wrong color displayed.

1. See the preceding note on replacing LCDs.
2. Reseat all LCD connectors.
3. LCD Assembly
4. System Board
5. Video Card
6. Interposer Card

LCD has extra horizontal or vertical lines displayed.

LCD Assembly

Model 755CDV Symptoms:

Symptom/Error

FRU/Action

The screen is black when the LCD cover is installed.

1. Verify that the LCD cover is firmly installed on the LCD.
2. Diagnose the LCD assembly by following "LCD Related Symptoms" on.

The LCD is wavy when the computer is placed on the overhead projector.

Some overhead projectors interfere with the LCD of the computer. Use another
overhead projector.

The LCD stays on even when the LCD cover is removed.

Make sure that the switch on the rear of the LCD is not stuck. If it is stuck, release it with the tip of a ball-point pen.

- Abnormal screen
- Uneven color on the screen
- Spot on the screen

1. Check that the white film on the LCD cover is clean. Gently wipe the film
with a dry, soft cloth, such as a lens cleaner.
2. LCD Cover
3. Diagnose the LCD assembly by following "LCD Related Symptoms" on.

Note:
The customer may be responsible for repair costs if the LCD cover was damaged due to misuse, excessive force, scratch, or liquid spilled by the customer.

The computer has an intermittent problem when you use it on the overhead projector.

Problem such as high environmental temperature might be the cause. Use the stand supplied with the computer.

The remote control does not work.

1. Check that two AAA alkaline batteries are installed in the remote control.
2. Check that two AAA alkaline batteries in the remote control are at their normal energy (voltage) level.
3. Enable the IR port of the computer with the ThinkPad Features program.
(Disable the serial port at this time.)
4. Refer to the trouble shooting section in the Help menu of the Mind Path
Presentation F/X program. Set up this program following the guide.
5. If the preceding items are correct, the radiation from the light of the overhead projector might be interfering the IR port of the computer. Disable the rear IR port of the computer, and use the remote control with the front IR port.
6. Use the remote control with another computer, which IR port works normally. If the remote control does not work, the remote control is not working properly.

If there is still a problem, refer to "Infrared Related Symptoms".

Keyboard/TrackPoint III Related Symptoms:

Symptom/Error

FRU/Action

Keyboard (one or more keys) does not work.

1. Reseat the three keyboard cables.
2. Keyboard
3. Video Card
4. System Board

TrackPoint III does not work.

1. Go to "TrackPoint III Checkout".
2. Keyboard
3. Video Card
4. System Board

Pointer moves automatically or does not work correctly.

1. See "TrackPoint III Checkout".

Indicator Related Symptoms:

Symptom/Error

FRU/Action

Indicator incorrectly remains off or on, but system runs correctly.

1. Reseat the status indicator cable.
2. Status Indicator
3. Interposer Card
4. System Board

Battery power status indicator blinks from green, yellow, to orange.

1. Check that a correct battery is installed.
2. Set the battery storage switch to ON.
3. Battery Pack
4. DC/DC Card
5. System Board

Power Related Symptoms:

Symptom/Error

FRU/Action

Power shut down during operation.

1. Go to "Power Systems Checkout".
2. Battery Pack
3. Remove the battery pack and let it cool for two hours.
4. DC/DC Card
5. Power sources

The system will not power-off.
(See "Reset Pushbutton" .)

1. Press the Reset pushbutton.
2. System Board

Function/Audio Related Symptoms:

Symptom/Error

FRU/Action

The system will not suspend or resume by opening or closing the keyboard.

1. Go to "Suspend Mode" and check that the computer can enter suspend mode.
2. DC/DC Card
3. Video Card
4. System Board

The system will not suspend or resume by opening or closing the LCD.

1. Go to "Suspend Mode" and that check that the computer can enter suspend mode.
2. Top Cover
3. DC/DC Card
4. System Board

Battery Fuel-Gauge does not go higher than 90%.

Go to "Checking the Battery Pack" and see the note.

Memory count (size) appears differently from actual size.

Go to "Memory Checkout".

System configuration does not match the installed devices.

Go to "Checking the Installed Devices List".

System hangs intermittently.

Go to "Intermittent Problems".

Peripheral Device Related Symptoms:

Symptom/Error

FRU/Action

External display does not work correctly.

1. See "External Display Self-Test" in "Common Devices Checkout" section.

Printer problems.

1. Run Printer Self-test.
2. Parallel Port Device
3. Cable
4. System Board

Serial or parallel port device problems.

1. Device
2. Device Cable
3. System Board

Search Keywords

Hint Category

Hardware Maintenance Information

Date Created

15-11-96

Last Updated

27-08-98

Revision Date

18-08-99

Brand

IBM ThinkPad

Product Family

ThinkPad 755CD, ThinkPad 755CDV

Machine Type

9545

Model

Various

TypeModel

Retain Tip (if applicable)

N/A

Reverse Doclinks
and Admin Purposes

Symptom/Error	FRU/Action
No beep, power-on indicator on, and a blank LCD during POST.	1. System Board 2. DC/DC Card 3. Video Card 4. Processor Card
LCD backlight not working, or LCD too dark, or LCD brightness cannot be adjusted, or LCD contrast cannot be adjusted.	1. Reseat the LCD connectors. 2. LCD Assembly 3. Interposer Card 4. DC/DC Card
LCD screen unreadable, or Characters missing pels, or Screen abnormal, or Wrong color displayed.	1. See the preceding note on replacing LCDs. 2. Reseat all LCD connectors. 3. LCD Assembly 4. System Board 5. Video Card 6. Interposer Card
LCD has extra horizontal or vertical lines displayed.	LCD Assembly

Symptom/Error	FRU/Action
The screen is black when the LCD cover is installed.	1. Verify that the LCD cover is firmly installed on the LCD. 2. Diagnose the LCD assembly by following "LCD Related Symptoms" on.
The LCD is wavy when the computer is placed on the overhead projector.	Some overhead projectors interfere with the LCD of the computer. Use another overhead projector.
The LCD stays on even when the LCD cover is removed.	Make sure that the switch on the rear of the LCD is not stuck. If it is stuck, release it with the tip of a ball-point pen.
- Abnormal screen - Uneven color on the screen - Spot on the screen	1. Check that the white film on the LCD cover is clean. Gently wipe the film with a dry, soft cloth, such as a lens cleaner. 2. LCD Cover 3. Diagnose the LCD assembly by following "LCD Related Symptoms" on. Note: The customer may be responsible for repair costs if the LCD cover was damaged due to misuse, excessive force, scratch, or liquid spilled by the customer.
The computer has an intermittent problem when you use it on the overhead projector.	Problem such as high environmental temperature might be the cause. Use the stand supplied with the computer.
The remote control does not work.	1. Check that two AAA alkaline batteries are installed in the remote control. 2. Check that two AAA alkaline batteries in the remote control are at their normal energy (voltage) level. 3. Enable the IR port of the computer with the ThinkPad Features program. (Disable the serial port at this time.) 4. Refer to the trouble shooting section in the Help menu of the Mind Path Presentation F/X program. Set up this program following the guide. 5. If the preceding items are correct, the radiation from the light of the overhead projector might be interfering the IR port of the computer. Disable the rear IR port of the computer, and use the remote control with the front IR port. 6. Use the remote control with another computer, which IR port works normally. If the remote control does not work, the remote control is not working properly. If there is still a problem, refer to "Infrared Related Symptoms".

Symptom/Error	FRU/Action
Keyboard (one or more keys) does not work.	1. Reseat the three keyboard cables. 2. Keyboard 3. Video Card 4. System Board
TrackPoint III does not work.	1. Go to "TrackPoint III Checkout". 2. Keyboard 3. Video Card 4. System Board
Pointer moves automatically or does not work correctly.	1. See "TrackPoint III Checkout".

Symptom/Error	FRU/Action
Indicator incorrectly remains off or on, but system runs correctly.	1. Reseat the status indicator cable. 2. Status Indicator 3. Interposer Card 4. System Board
Battery power status indicator blinks from green, yellow, to orange.	1. Check that a correct battery is installed. 2. Set the battery storage switch to ON. 3. Battery Pack 4. DC/DC Card 5. System Board

Symptom/Error	FRU/Action
Power shut down during operation.	1. Go to "Power Systems Checkout". 2. Battery Pack 3. Remove the battery pack and let it cool for two hours. 4. DC/DC Card 5. Power sources
The system will not power-off. (See "Reset Pushbutton" .)	1. Press the Reset pushbutton. 2. System Board

Symptom/Error	FRU/Action
The system will not suspend or resume by opening or closing the keyboard.	1. Go to "Suspend Mode" and check that the computer can enter suspend mode. 2. DC/DC Card 3. Video Card 4. System Board
The system will not suspend or resume by opening or closing the LCD.	1. Go to "Suspend Mode" and that check that the computer can enter suspend mode. 2. Top Cover 3. DC/DC Card 4. System Board
Battery Fuel-Gauge does not go higher than 90%.	Go to "Checking the Battery Pack" and see the note.
Memory count (size) appears differently from actual size.	Go to "Memory Checkout".
System configuration does not match the installed devices.	Go to "Checking the Installed Devices List".
System hangs intermittently.	Go to "Intermittent Problems".

Symptom/Error	FRU/Action
External display does not work correctly.	1. See "External Display Self-Test" in "Common Devices Checkout" section.
Printer problems.	1. Run Printer Self-test. 2. Parallel Port Device 3. Cable 4. System Board
Serial or parallel port device problems.	1. Device 2. Device Cable 3. System Board

	Search Keywords
	Hint Category	Hardware Maintenance Information
	Date Created	15-11-96
	Last Updated	27-08-98
	Revision Date	18-08-99
	Brand	IBM ThinkPad
	Product Family	ThinkPad 755CD, ThinkPad 755CDV
	Machine Type	9545
	Model	Various
	TypeModel
	Retain Tip (if applicable)	N/A
	Reverse Doclinks and Admin Purposes