Beep Codes; Table 4-2 Beep Code Descriptions - NEC Direction T-Series Manual

4-10 Maintenance and Troubleshooting

Beep Codes

During boot up, the computer performs a series of POST (Power On Self Test) routines. A
beep code may appear when an error is detected. There are fatal and nonfatal errors. The
fatal errors include BIOS, CMOS, DMA, RAM, video, and keyboard controller errors. The
nonfatal errors include timer tick interrupt, shutdown test, unexpected interrupt in protected
mode, gate A20, RAM test, interval timer channel 2 test, clock, serial and parallel port test,
math co-processor, system board select, and extended CMOS RAM.
The following table provides a description of the beep codes.
Beeps Error Message
1 Refresh Failure
2 Parity Error
3 Base 64 KB Memory Failure
4 Timer Not Operational
5 Processor Error
6 8042 - Gate A20 Failure
7 Processor Exception Interrupt
Error
8 Display Memory Read/Write Error
9
ROM Checksum Error
10 CMOS Shutdown Register
Read/Write Error

Table 4-2 Beep Code Descriptions

Description
The memory refresh circuitry on the system
board is faulty.
Parity error in the first 64 KB of memory.
Memory failure in the first 64 KB.
Memory failure in the first 64 KB of
memory, or Timer 1 on the system board is
not functioning.
The CPU on the system board generated
an error.
The keyboard controller (8042) may be
bad. The BIOS cannot switch to protected
mode.
The CPU generated an exception interrupt.
The system graphics adapter is either
missing or its memory is faulty. This is not
a fatal error.
ROM checksum value does not match the
value encoded in BIOS.
The shutdown register for CMOS RAM
failed.