Technical information

What If Your Computer Does Not Work?
Problem Action
The screen image
appears smaller than the
LCD size (using a DOS
application on a 755CX
SVGA model only).
This is to maintain compatibility with the DOS application; it is not a problem.
When you use DOS Shell
or some kind of
application in the DOS
environment, the lines on
the screen are disordered.
(755CX SVGA model
only)
Verify that:
If you are using DOS Shell and have set the screen mode 800-by-600
resolution with the PS2 MODE3X command, do the following:
1. At the DOS Shell screen, select Options from the menu bar; then select
Display....
2. Select Graphics 30 lines Medium Resolution 1; then select OK.
The screen will recover.
If you are using an application other than DOS Shell, do the following:
– At the DOS command prompt, type PS2 MODE3X OFF; then press
Enter.
The screen stays on
although the power switch
is turned off.
Press the Power Shutdown switch on the rear of the computer with the tip of a
pen to turn off the computer; then turn the computer on again.
The computer goes into
suspend mode
immediately after the
POST. (The suspend
mode indicator turns on.)
Verify that:
The battery pack is charged. (The battery power status indicator is green or
yellow.)
Keyboard is firmly closed.
When the external display is attached to the computer, the Will not
suspend even if LCD is closed option (in the Suspend/Resume options of
the ThinkPad Features program) is not enabled. (See page 35.)
The environmental temperature is in an acceptable range. Refer to
“Specifications” on page 251.
If the preceding items are correct, have the computer serviced.
Error 190 appears and the
computer immediately
turns off.
The battery pack is low in power. Connect the AC Adapter to the computer, or
replace the battery pack with a fully charged one.
Missing, discolored, or
bright dots appear on the
screen at all times.
The computer LCD contains more than 1440 000 (for the 755CX SVGA model)
or 921 000 (for the 755CX VGA model) thin-film transistors (TFTs). A small
number of missing, discolored, or bright dots on the screen is an intrinsic
characteristic of TFT LCD technology and is not an LCD defect.
Chapter 8. Solving Computer Problems 205