Maintenance and Troubleshooting 4-17
Beep Codes
One beep indicates that the system has completed its power-on self-test. If a long beep or a
series of long beeps occurs, power off the computer and try again. If the long beeps persist,
see Table 4-5 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 indicate a failure in the first 64 K of RAM.
Table 4-5 Diagnostic Beep Codes
Message
Beeps
Description of Failure
Refresh Failure
1
The memory refresh circuit on the system board is
faulty.
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’s video adapter 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
11
The cache is faulty.
CMOS Battery Replacement
Remove the 3-volt lithium battery from system board as follows:
1.
Turn off and unplug the system unit and any external option connected to it.
2.
Remove the system unit cover.
Summary of Contents for MT-2550-24874C
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