This page is about one of the most annoying things in the PS/2 World -
Error codes. They come up when you need them the least and -often- don't tell
much why anything went wrong.
(* indicates a short beep, _ means a long beep)
General Error Codes (from The Microchannel Enthusist's Page)
Major Error Code -----------+---+ | | | | Trailing Zeros -------- 0024 01XX to fill 8 digits || || Minor (diagnostic Error Code)----++
The Error Code is written in the 4 + 4 style as it appears on a PS/2 Mod. 95 LED-panel and in the Premium Line "extended 8-digits" form. The bold part in the middle is the so called "Major Error Code" and -basically and in large parts- identical with the PC/AT Error Codes and those used on earlier PS/2 machines.
The 2 digits of the "Minor Error Code" is dependent on the type of the error and -mostly- only specified when running the Advanced Diagnostics. The minor error code is however often given at POST-Errors (after restarting the computer) and might specify a particular error condition. In case the minor error code is marked with "XX" in the follow-up error lists it means "Don't care" and it can be any character.
Error messages generally consist of eight characters. If an error message appears as a 12-character message, disregard the last four characters.
The following errors are all listed as eight-character messages. Messages might appear on your screen as three-, four-, or five-character messages. When this occurs, always add two zeros ["00"] to the RIGHT of the code, and add enough zeros "0" to the LEFT of the code to reach eight characters.
Error Code Format Examples:
00030100 - Three-character, Codes 300 - 999
Error Code Listing:
Error Code Tables:
For a chart how to determine a failing memory module on
Mod. 56/57, 76/77, 85 and 90/95 see HERE.
These have to do with the Initial Microcode Load on the 76/77, 85, 90, 95, and 500 systems.(and the TP700/720!) see HERE.
General SCSI Error Codes
Device Size Code -----------------+ +--------- Unit Reference Code | | Adapter MCA-Slot ----------------+| |+-------- Sense Key Code || || Logical Unit Number ---------------+|| || +------ Additional Sense Code ||| || | Physical Unit Number --------------+||| || | |||| || | Device Code Number ---------+--+ |||| || | | | |||| ||++ | | |||| |||| 0210 401H 9231
Basically the SCSI Error Codes consist out of an 8-character
output like a General Error Code, but have an additional 4-character Error
Return Code at the end, which helps to specify the nature of the error.
If multiple errors occur during POST, resolve them in the order that
they are presented.
Note: The correct procedure for using
the Personal System/2 reference diskette is to power on the system with the
diskette inserted in the diskette drive. Soft booting the reference diskette
(ie. Ctrl-Alt-Del) may cause false errors as well as a false indication that
a power-on password is already present when you try to set one.
Ed. I can't remember having issues
from a warm boot while working on a PS/2, -BUT- if the system refuses to apply
configuration changes, cold boot.
Always cold boot and run Advanced Diagnostics (go into System Programs and at the main menu do a Ctrl-A) before replacing components when trying to resolve software problems. If diags don't fail, replacing components will probably not solve the problem. Refer to the software vendor for possible patches. The software may not be supported on the system.
Multiple POST Error Procedure
If more than one error code is displayed, diagnose the first error code first. The cause of the first error code could cause other devices to fail. This is especially important with configuration errors.
If no error codes appear, see if the error symptoms are listed in the Error list.
If an adapter consists of multiple FRUs (memory for example) remove the optional FRUs one at a time to see if symptoms change before replacing the adapter.
External surge suppressors may be the source for hard to diagnose problems.
Dead System (no POST, screen blank, no beep)
The most likely cause is a device that is shorting out the power supply. An improperly inserted memory module, a defective adapter or device can cause a short circuit. To prevent damage to a power supply, the system board must present a "Power Good" signal to the power supply in 150 ms or less. If this does not occur, then the power supply shuts down internally.
Known dufus tricks- SIMM inserted backwards (with enough force ANYTHING is possible). adapter not fully seated in expansion slot, power cord not plugged in, unsupported/defective adapter (Non-IBM adapter, like ALR..), or with a heavily loaded system, too many drives starting at once (overcurrent as the drives attempt to spin up- leave motor start jumper open to start drives after the controller interrogates them).
Troubleshooting a Dead System
Defective or weak batteries can cause loss of all setup information. If only part of the setup is lost, the battery is probably NOT the cause. Inaccurate time is usually caused by software, but some of the older models with the 6V batteries are more prone to time slowing down.
Clearing 96 8N1 (From Peter Wendt)
IBM wrote in the HMM "Remove the battery, then wait 5
minutes ..." (HMM, September 1993, P/N 71G9316, page 300,
"96 8N1 Error Message") but empirical research showed that
this doesn't work fairly often.
That worked any time I'd landed on the "ASCII-console
mode" during fiddling with SOD- / bad-DMA platforms and
Kingston Turbochips :-) Moving only the jumper or only
isolating the battery often did *not* cure it. Which is
It may be necessary to move the power-on password jumper (J16-8595 or J10 - 8590) to enable an IML to the reference diskette in drive a. Moving this jumper forces the stage 1 POST routine to branch to the diskette, rather than attempt to load stage 2 from the Fixed disk system partition. (A reference diskette must be present in the a: drive)
The Stage 2 POST code on the reference diskette is identical to the code loaded onto the system partition, Moving this jumper sets all default values, except ASCII terminal mode. It should be further noted, that moving the Power-On password jumper is effective for only 1 Power-On cycle because stage 1 POST tracks (records) the position of the jumper each time it is run.