Beep Codes; Cmos Battery Replacement; Diagnostic Beep Codes - NEC POWERMATE PROFESSIONAL - SERVICE MANUAL 05-1997 Service Manual

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.
Message
Refresh Failure
Base 64 KB Memory Failure
Timer Not Operational
Processor Error
8042 – Gate A20 Failure
Processor Exception Interrupt
Error
Display Memory Read/Write
Error
ROM Checksum Error
CMOS Shutdown Register
Read/Write Error
Cache Error

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.
Remove the system unit cover.
2.
Table 4-5 Diagnostic Beep Codes
Beeps Description of Failure
1 The memory refresh circuit on the system board is
faulty.
3 Memory failure in the first 64 KB.
4 Memory failure in the 64 KB of memory or timer 1
on the system board is not functioning.
5 The CPU on the system board generated an error.
6 The keyboard controller (8042) may be bad. The
BIOS cannot switch to protect mode.
7 The CPU generated an exception interrupt.
8 The system's video adapter is either missing or its
memory is faulty. This is not a fatal error.
9 ROM checksum value does not match the value
encoded in the BIOS.
10 The shutdown register for CMOS RAM failed.
11 The cache is faulty.
Maintenance and Troubleshooting 4-17