This article was previously published under Q76922
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In the event that a RAM or ROM chip fails, a multidigit error codewill be displayed. The error code is displayed only briefly, thenreplaced by the message
PARITY CHECK x
where if x=1, the problem is on the system board or is power supplyproblem, and if x=2, the problem is on one of the memory expansionadapters.
The multidigit error codes can be used to determine where the chiperror occurred.
ROM Error Codes
During power-on-self-test (POST), a failed ROM chip willdisplay an error code in the following format
where xx is the hexadecimal address of the failed ROM.
Not all problems can be identified by an error code, because someproblems will prevent the computer from booting at all.
The following table shows some of the possible error codesand what they mean:
Error Code Computer Location of Faulty ROM---------- -------- ----------------------C800 ROM All Hard disk drive adapterCC00 ROM PC,XT PC networkIO ROM CC00 XT 286,AT PC networkF600 ROM PC U29F800 ROM PC U30FA00 ROM PC U31FC00 ROM PC U32Fxxx ROM PC System boardROM Error all System boardIO ROM xxxxxx XT 286, AT Power related
RAM Error Codes
When the last three numbers of an error code are 201, it indicates anerror in the RAM area. The numbers preceding 201 are the code thatidentifies the specific chip. Error code formats appear as follows:
Computer Error Code Format-------- -----------------PC xxx 201XT xxxxx xx 201AT and PS/2 xxxxxx xxxx 201
Note: x represents hexadecimal characters.
The first one or two characters indicate the bank or expansionadapter, and the two to four characters preceding 201 represent thespecific chip that failed.
If a chip has failed in one of the first few memory banks, the errorcode may disappear very quickly. Ensure that the display is warmed-upsufficiently to show the error code.
For more information, query on the following words:
parity error and meaning and message
parity check and error and description
"The PC Configuration Handbook," John Woram, pages 259-275, Bantam,1990
"IBM PC Troubleshooting and Repair Guide," Robert C. Brenner, H.W.Sams & Co., 1985