Check Procedures     37
Index of Symptoms, Messages, Error Codes, or Beeps 
How to Use Error Messages:
 Use the messages, error codes, and beeps 
combinations that occur to diagnose failures. If more than one failure occurs, 
begin the diagnosis from the first failure that appeared. The cause of the first 
failure can result in false messages, error codes, or beeps. If you did not 
receive any messages, error codes, or beeps, see if the symptom is listed in 
“Table 2-3 Error Symptoms List” on page 44.
CAUTION: 
 When you have deemed it necessary to replace a FRU, and have 
done so, you must run a total system check to ensure that no other 
activity has been affected by the change. This system check can be 
done through the diagnostics program (Select Diagnostics, then select 
and execute All Tests from PC-Doctor).
POST:
 Some diagnostic aids are resident in the machine, such as the Power-
On Self Test (POST). The machine performs the POST each time it is powered 
on. Use this information throughout the diagnostic procedures. The POST is a 
series of system checks and initializations that verify the correct operation of 
the base system. 
After a successful POST, the system attempts to load operating system. The 
system can be customized for different startup (boot) methods by the BIOS 
Setup Utility. “Startup Options” on page 21.
The system's default startup sequence automatically looks for the operating 
system files in the hard disk if these files are not found in the diskette.
WARNING: 
Remember that POST does not test all areas, but only those that 
allow the system to operate well enough to run the diagnostics program. 
Table 2-1 lists BIOS error codes, messages, to their possible causes. table 2-2 
lists BIOS beeps to their possible causes. Table 2-3 lists error symptoms and 
their possible causes. The most likely cause is listed first. Make sure you 
complete all items in the cause or “Action/FRU” column. When servicing a 
system, always begin with “Start” on page 33.
If you are unable to correct the problem using these two index tables, go to 
“Undetermined Problems” on page 70.
NOTE: 
 
1. If an error message and incorrect audio response occur, diagnose the error 
message first.
2. If you cannot run the diagnostics program tests but did receive a POST error 
code and message, use “Table 2-1 POST Error Codes and Messages List” 
on page 38 to diagnose system problems. 
3. If you cannot run the diagnostics program tests but did receive a POST error