Maintenance and Troubleshooting 4-11
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,
numeric processor, system board select, and extended CMOS RAM.
The following table provides a description of the beep codes.
Table 4-3 Beep Code Descriptions
Beeps
Description
1-2
Search for option ROMs
1-2-2-3
BIOS ROM checksum
1-3-1-1
Test DRAM refresh
1-3-1-3
Test keyboard controller
1-3-3-1
Autosize DRAM
1-3-3-2
Initialize POST memory manager
1-3-3-3
Clear 512 KB base RAM
1-3-4-1
RAM failure on address line xxxx
1-3-4-3
RAM failure on data bits xxxx of low byte of memory bus
1-4-1-1
RAM failure on data bits xxxx of high byte of memory bus
2-1-2-2
POST device initialization
2-1-2-3
Check ROM copyright notice
2-2-3-1
Test for unexpected interrupts
2-2-4-1
Test RAM between 512 KB and 640 KB
