Quick Reference Guide 37
Error Messages
NOTE: If the message is not listed, see the documentation for either the operating system or the program that was
running when the message appeared.
If an error occurs during start-up, a message may be displayed on the monitor identifying the problem.
See"Error Messages" in the
User’s Guide
for suggestions on resolving any problems.
Diagnostic Lights CAUTION: Before you begin any of the procedures in this section, follow the safety instructions located
inthe Product Information Guide.
To help you troubleshoot a problem, your computer has four lights labeled "1," "2," "3," and "4" on the front.
The lights can be off or green. When the computer starts normally, the lights flash. After the computer
starts, all four lights display solid green briefly and then turn off to indicate normal operation. If the
computer malfunctions, the pattern of the lights identify the problem.
3-4-2 Screen retrace failure
3-4-3 Search for video ROM failure
4-2-1 No timer tick
4-2-2 Shutdown failure
4-2-3 Gate A20 failure
4-2-4 Unexpected interrupt in protected mode
4-3-1 Memory failure above address 0FFFFh
4-3-3 Timer-chip counter 2 failure
4-3-4 Time-of-day clock stopped
4-4-1 Serial or parallel port test failure
4-4-2 Failure to decompress code to shadowed memory
4-4-3 Math-coprocessor test failure
4-4-4 Cache test failure
Light Pattern Problem Description Suggested Resolution
The computer is in a normal off
condition or a possible pre-BIOS
failurehas occurred.
NOTE: The diagnostic lights turn off after
a short time if the computer is in a normal
operating condition after POST.
Plug the computer into a working
electrical outlet and press the power
button.
Code Cause