IBM Thinkpad A20mp A21mp A22mp Manual

Indicator Meaning

4Num lockGreen:The numeric keypad on the keyboard
is enabled. To enable or disable the
keypad, press and hold the Shift key
while pressing the NumLk key.

5Caps lockGreen:Caps Lock mode is enabled. To
enable or disable Caps Lock mode,
press Caps Lock key.

6Scroll lockGreen:Scroll Lock mode is enabled. Arrow
keys can be used as screen-scroll
function keys, but not to move the
cursor. To enable or disable Scroll
Lock mode, press ScrLk key. Not all
application programs support this...

FRU tests
The following table shows the test for each FRU.
FRU Applicable test
System board 1.Diagnostics-->CPU/Coprocessor
2.Diagnostics-->Systemboard
PowerDiagnostics-->Other Devices-->IBM AC
Adapter,IBM Battery 1 (IBM Battery 2)
LCD unit 1.Diagnostics-->Video Adapter
2.Interactive Tests-->Video
Modem 1. Make sure the modem is set up correctly.
2. Replace the modem jack and the modem
card in turn, and run the following test in
Diagnostics-->Communication:
a. Lucent Modem (M2) Loopback
b. Lucent Modem...

FRU Applicable test
CD-ROM or
DVD drive1.Diagnostics-->Other Devices-->
CD-ROM/DVD
2.Interactive Tests-->CD-ROM/DVD Test
Memory 1. If two DIMMs are installed, remove one of
them and runDiagnostics-->Memory
Test - Quick.
2. If the problem does not recur, return the
DIMM to its place, remove the other one,
and run the test again.
3. If the test does not detect the error, run
Diagnostics-->Memory Test - Full.
Fan 1. Turn on the computer and check the air
turbulence at the louver near the power
switch.
2....

Fn key combinations
The following table shows the function of each combination
of Fn with a function key.
Key
combinationDescription
Fn + F1 Reserved.
Fn + F2 Reserved.
Fn + F3 Turn off the LCD display, leaving the screen
blank. To turn the LCD display on again, press
any key or the TrackPoint stick.
Fn + F4 Turn standby mode on. To return to normal
operation, press the Fn key independently,
without pressing a function key.
Fn + F5 Reserved.
Fn + F6 Reserved.
Fn + F7 Switch between the LCD and an...

Symptom-to-FRU index
The symptom-to-FRU index in this section lists symptoms
and errors and their possible causes. The most likely
cause is listed first, in boldface type.
Note:Do the FRU replacement or other actions in the
sequence shown in the column headed“FRU or
action, in sequence.”If replacing a FRU does not
solve the problem, put the original part back in the
computer. Do not replace a nondefective FRU.
This index can also help you determine, during regular
servicing, what FRUs are likely to need...

Symptom or error FRU or action, in sequence
0190
Critical low battery error.1.Charge the battery pack.
2. Battery pack.
0193
RF antenna has been removed.Enter the supervisor
password.
0194
The computer has been carried
through a security gate.Enter the supervisor
password.
0200
Hard disk error—The hard
disk is not working.1.Reseat the hard-disk
drive.
2. Load Setup Defaults in IBM
BIOS Setup Utility.
3. Hard-disk drive.
4. System board.
021x
Stuck key—Keyboard error.Run interactive tests of the
keyboard...

Symptom or error FRU or action, in sequence
0270
Real-time clock error.1.Replace the backup
battery and run IBM BIOS
Setup Utility to reset the
time and date.
2. System board.
0271
Date and time error—Neither
the date nor the time is set in
the computer.Run IBM BIOS Setup Utility to
reset the time and date.
02B2
Incorrect drive A type.1.Diskette drive.
2. External FDD cable.
3. I/O card.
02F4
EISA CMOS not writable.1.Load Setup Defaults in
IBM BIOS Setup Utility.
2. Replace the backup battery.
3. System...

Error messages
Symptom or error FRU or action, in sequence
Device address conflict. 1.Load Setup Defaults in
IBM BIOS Setup Utility.
2. Backup battery.
3. System board.
Allocation error for device. 1.Load Setup Defaults in
IBM BIOS Setup Utility.
2. Backup battery.
3. System board.
Failing bits: nnnn. 1.DIMM.
2. System board.
Invalid system configuration
data.1.DIMM.
2. System board.
I/O device IRQ conflict. 1.Load Setup Defaults in
IBM BIOS Setup Utility.
2. Backup battery.
3. System board.
Operating...

Beep symptoms
Symptom or error FRU or action, in sequence
One beep and a blank,
unreadable, or flashing LCD.1.Reseat the LCD
connector.
2. LCD assembly.
3. External CRT.
4. System board.
One long and two short beeps,
and a blank or unreadable
LCD.1.System board.
2. LCD assembly.
3. DIMM.
Two short beeps with error
codes.POST error. See“Numeric
error codes”on page 49.
Two short beeps with blank
screen.1.System board.
2. DIMM.
Two or more beeps, or a
continuous beep. Operating
System starts successfully.If...

LCD-related symptoms
ImportantThe TFT LCD for the notebook computer contains
many thin-film transistors (TFTs). A small number of
dots that are missing, discolored, or always lighted
is characteristic of TFT LCD technology, but
excessive pixel problems can cause viewing
concerns. The LCD should be replaced if the
number of missing, discolored, or lighted dots in any
background is:
vSVGA:5 or more bright dots, 5 or more dark
dots, or a total of 9 or more bright and dark dots.
vXGA:8 or more bright dots, 8...