Maintenance and Troubleshooting 4-11
Table Section 4-6 Problems and Solutions
Problem Symptom Solution
Communication
error
No or bad data when
communicating.
1. Check cable connections between
system board and device.
2. Check that the interface port is
selected.
3. Test or replace device and interface
cable.
4. Replace system board.
Beep Codes
One beep indicates that the computer has completed its power-on self-test. If a long beep or
a series of long beeps occur, power off the computer and try again. If the long beeps per-
sists, see Table Section 4-7 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 4-7 Diagnostic Beep Codes
Message Beeps Description of Failure
Refresh failure 1 The memory refresh circuitry 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 (8042) 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.
To Next Page
Loading...
