Troubleshooting Dead System
CheckPoint Codes (CP codes on Model 95 LED)
System Will Not POST - [Breadboarding]
POST Errors [errors displayed on screen]
Multiple POST Errors
General Error Codes
118 Error Code [Memory error logging process 8590 and 8595]
2xx error - Failing memory location, size, speed and type [Mod. 56/57, 76/77, 85 and 90/95]
SCSI Error Codes
SCSI Fixed Disk Diagnostic Error Return Codes
IML Error Codes (I99xxxx)
Initial Microcode Load on the 76/77, 85, 90, 95, 500 - and the TP700/720!
Clearing the 96 8N1 code [console mode selected!]
Multiple POST Error Procedure
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.
System (no POST, screen blank, no
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)
Intermittent and very difficult to diagnose system
problems, may be caused by line cords which are not
fully seated, or are too loose to make a tight
line cord from outlet before working on line cord
Replacing the line cord may be necessary in some cases.
Both ends of the line cord should be checked.
2. Remove all adapters, options,
extra memory, etc.
3. Plug in, power on, listen for a
beep. The beep indicates POST has run. Multiple
beeps may occur.
4A. If no beep is heard, verify continuity through
NOTE: On systems with LogicLock, the switches used to detect unauthorized access might be put in the wrong position during case re-installation.
Unit does not run with cover removed (9556/57 9576/77)
4B. If a beep occurs, reinstall adapters one at a
time and return to step 3. When
Clearing 96 8N1
From Peter Wendt-
Do the following:
- push a piece of card under the CMOS-buffer battery clip to have it isolated
- toggle the Password Override Jumper
- wait 20 minutes
- remove the card from under the battery clip
- start the system with a known good board & appropriate ref.disk
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
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