Beep Codes; Beep Codes For Fatal Errors - Digital Equipment DECpc LPv 425sx Service Maintenance Manual

Troubleshooting

Beep Codes

If the POST finds an error and cannot display a message, the computer's speaker emits a series of beeps to
indicate the error and places a value in I/O port 80h.
For example, a failure of bit 3 in the first 64 KB of RAM is indicated by a 2-1-4 beep code (a burst of two
beeps, a single beepand a burst of four beeps).
The table below lists the beep codes and the values the POST writes to I/O port 80h when it encounters a
fatal error. This table lists fatal errors that lock up the computer. Nonfatal errors that do not lock up the
computer are listed in a separate table.

Beep Codes for Fatal Errors

Beep Code
1-1-3
1-1-4
1-2-1
1-2-2
1-2-3
1-3-1
1-3-3
1-3-4
1-4-1
1-4-2
2-1-1
2-1-2
2-1-3
2-1-4
2-2-1
2-2-2
2-2-3
2-2-4
2-3-1
2-3-2
2-3-3
2-3-4
2-4-1
2-4-2
2-4-3
2-4-4
3-1-1
3-1-2
3-1-3
3-1-4
3-2-4
4-2-1
4-2-2
52
Error Message
CMOS write/read failure
ROM checksum failure
Interval timer failure
DMA failure
DMA page register write/read failure
RAM refresh failure
1st 64 KB RAM chip or data line failure
1st 64 KB RAM odd/even logic failure
1st 64 KB RAM address line failure
1st 64 KB RAM parity failure
Bit 0 1st 64 KB RAM failure
Bit 1 1st 64 KB RAM failure
Bit 2 1st 64 KB RAM failure
Bit 3 1st 64 KB RAM failure
Bit 4 1st 64 KB RAM failure
Bit 5 1st 64 KB RAM failure
Bit 6 1st 64 KB RAM failure
Bit 7 1st 64 KB RAM failure
Bit 8 1st 64 KB RAM failure
Bit 9 1st 64 KB RAM failure
Bit A 1st 64 KB RAM failure
Bit B 1st 64 KB RAM failure
Bit C 1st 64 KB RAM failure
Bit D 1st 64 KB RAM failure
Bit E 1st 64 KB RAM failure
Bit F 1st 64 KB RAM failure
Slave DMA register failure
Master DMA register failure
Master interrupt mask register failure
Slave interrupt mask register failure
Keyboard/mouse controller failure
Timer tick interrupt failure
Shutdown failure
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