Beep Codes; Cmos Battery Replacement; Table 4-3 Beep Code Descriptions - NEC DIRECTION L Service Manual

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 Description
1 One short beep before boot
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 8742 keyboard controller
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
2-1-2-3
Check ROM copyright notice
2-2-3-1 Test for unexpected interrupts

CMOS Battery Replacement

Remove the 3-volt lithium battery from the system board as follows.
Turn off and unplug the system unit and any external options connected to the
1.
system.
Remove the system access cover.
2.

Table 4-3 Beep Code Descriptions

CAUTION: Removing the battery from the
system board causes the computer to lose system
configuration information. If possible, run Setup
and record the system configuration settings
before removing the battery. Use that
information to restore the system after replacing
the battery.
Maintenance and Troubleshooting 4-11