Maintenance and Troubleshooting 4-11
Beep Codes
One beep indicates that the system has completed its power-on self-test. If a long beep or a se-
ries of long beeps occur, power off the computer and try again. If the long beeps persists, see
Table Section 4-8
for the diagnostic beep codes.
The beep codes are announced on the speaker only if a fatal failure is detected. For instance,
three long beeps indicates a failure in the first 64 K of RAM.
Table Section 4-8 Diagnostic Beep Codes
Message
Beeps
Description of Failure
Refresh Failure
1
The memory refresh circuit on the system board is
faulty.
Parity Error
2
Parity error in the first 64 KB of memory.
Base 64 KB Memory Failure
3
Memory failure in the first 64 KB.
Timer Not Operational
4
Memory failure in the 64 KB of memory or timer 1 on
the system board is not functioning.
Processor Error
5
The CPU on the system board generated an error.
8042 – Gate A20 Failure
6
The keyboard controller may be bad. The BIOS
cannot switch to protect mode.
Processor Exception Interrupt
Error
7
The CPU generated an exception interrupt.
Display Memory Read/Write
Error
8
The system graphics is either missing or its memory is
faulty. This is not a fatal error.
ROM Checksum Error
9
ROM checksum value does not match the value
encoded in the BIOS.
CMOS Shutdown Register
Read/Write Error
10
The shutdown register for CMOS RAM failed.
Cache Error/External Cache Bad
11
The external cache is faulty.
