5-8 Troubleshooting and Repair
2.
Rolling ones test
- Several patterns are constructed. These patterns represent a
one rolling through the given location. For example, to roll a one through three
bits, the following patterns would be constructed: 001, 010, 011, 100, 101, 110,
and 111. The patterns are written to the location and then read back, one by one.
If the value read does not match the value written, the test is considered a failure.
3.
Rolling zeros test
- Several patterns are constructed. These patterns represent a
zero rolling through the given location. For example, to roll a zero through three
bits, the following patterns would be constructed: 011, 001, and 000. The patterns
are written to the location and then read back, one by one. If the value read does
not match the value written, the test is considered a failure.
4.
Checksum test
- All of the values in a given range of locations are added to-
gether. The range includes a location which when added to sum of the ranges, will
produce a known result, such as zero.
Beep Codes for System Board Errors
The following table provides system beep codes.
Table Section 5-4 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.
Summary of Contents for VERSA 500D WINDOWS 98 - UPGRADE INFORMATION
Page 79: ...4 8 Field Service Guidelines ...
Page 127: ...Index 3 ...
