Troubleshooting and Repair
Beep codes for system board errors Table 6-3 (a) BIOS Beep Codes
Beep
Code Diagnostic
Code
Description Test Performed
none 01h
CPU registers test in
progress or failure Pattern test of most of the 16-bit CPU
registers. Failure will result in a system
halt.
1-1-3 02h
CMOS write/read test in
progress or failure. Rolling ones test in the shutdown byte
(offset 0Eh) of the CMOS RAM. Failure
will result in a system halt.
1-1-4 03h
ROM BIOS checksum test in
progress or failure. The range of ROM that includes the
BIOS is checksummed. Failure will result
in a system halt.
1-2-1 04h
Programmable interval timer
0 test in progress or failure. Over a period of time, the current count
values in timer 0 are read and
accumulated by ORing them into the
values read so far. It is expected that
during the time period, all bits will be set.
Failure will result in a system halt.
1-2-2 05h
DMA channel 0 address and
count register test in progress
or failure.
Rolling ones and rolling zeros test of the
address and count registers of DMA
channel 0. Failure will result in a system
halt.
1-2-3 06h
DMA page register write/read
test in progress of failure. Pattern test of DMA page registers.
Failure will result in a system halt.
1-3-1 08h
RAM refresh verification test
in progress or failure. Over a period of time, the refresh bit (bit
4) in port 60h is read and tested. The
refresh bit should toggle from 0 to 1, then
1 to 0 within the time period. Failure will
result in system halt.
none 09h
First 64K RAM test in
progress. No specific test is performed - just
indicates that the test is beginning.
1-3-3 0Ah
First 64K RAM chip or data
line failure, multi-bit. The first 64K of RAM is tested with a
rolling ones test and a pattern test. If any
of the pattern tests fail, then the BIOS
reports that multiple data bits failure.
Failure results in a system halt.
1-4-2 0Dh Parity failure first 64K RAM At the completion of the rolling ones and
pattern tests of the first 64K, the BIOS
checks the parity error bits (bits 7 and 6)
of port 60h. Failure results in a system
halt.