Appendix B - Power On Self Test Codes

Beep Codes

Beep Codes are used to identify a Power On Self Test (POST) error that occurs when the screen is not available. Once the screen is operational, diagnostic messages are reported to the screen. There are beep codes for both fatal and nonfatal system board errors.

The codes are shown as x-y-z where 2-2-1 represents 2 beeps - pause - 2 beeps - pause - 1 beep.

Fatal Errors

1-1-1 CPU failure

1-1-3 CMOS failure

1-1-4 BIOS Checksum failure

1-2-1 8253 timer failure

1-2-2 DMA setup failure

1-2-3 DMA page register failure

1-3-1 RAM refresh not verified

1-3-2 SMI RAM bad

1-3-3 Low 64K RAM failure

1-3-4 Low 64K RAM even/odd failure

1-4-1 Low 64K RAM address line failure 1-4-2 Low 64K RAM parity error

2-1-1 Low 64K RAM bit 0 error 2-1-2 Low 64K RAM bit 1 error 2-1-3 Low 64K RAM bit 2 error 2-1-4 Low 64K RAM bit 3 error 2-2-1 Low 64K RAM bit 4 error 2-2-2 Low 64K RAM bit 5 error 2-2-3 Low 64K RAM bit 6 error 2-2-4 Low 64K RAM bit 7 error 2-3-1 Low 64K RAM bit 8 error 2-3-2 Low 64K RAM bit 9 error

2-3-3 Low 64K RAM bit 10 error

2-3-4 Low 64K RAM bit 11 error 2-4-1 Low 64K RAM bit 12 error 2-4-2 Low 64K RAM bit 13 error 2-4-3 Low 64K RAM bit 14 error 2-4-4 Low 64K RAM bit 15 error 3-1-1 DMA #2 register error 3-1-2 DMA #1 register error 3-1-3 8259 #1 error

3-1-4 8259 #2 error

3-2-4 8042 KB controller error

3-3-4 Video initialization error

3-4-1 Video retrace failure

3-4-2 Video ROM-scan in progress 3-4-3 Video ROM-scan error

Non-Fatal Errors

4-2-1 8253 timer tick test

4-2-2 Shutdown/Restart sequence

4-2-3 Gate A20 failure

4-2-4 Unexpected virtual mode interrupt

4-3-1 RAM test in progress

4-3-3 8253 timer channel 2 test 4-3-4 Time of day clock test 4-4-1 Serial port test

4-4-2 Parallel port test

4-4-3 Math coprocessor test

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