by
HbJ » Mon Dec 05, 2011 11:19 pm
The normal diagnostics are inaccessible in that state as the 3400 should freeze. This error hints towards dirt on the electrical connections or one or more broken board(s), most likely the CPU assembly.
If you have a Z80 board and it's broken I can send you a replacement from my spares.
Please follow these steps after you did electrically disconnect the GC and all accessories:
1.) Remove the upper cover of the 3400 (added fun when a 8100/8200 is installed). Left-hand you now have access to the electronics compartment.
2.) The main reason for this error is a fault at the door assembly. Check the electrical connectors of the door assembly which connects it over a flat ribbon cable to the main board (open and re-seat). Restart the GC so see if this did fix the error.
3.) Now connect the round connector "GND" with the connector "DIAG" (has a bar above the writing) on the CPU board with a crocodile clip. Then start just the GC and see if diagnostics starts. If so, you're getting an error code which should explain this mess. If not, proceed.
4.) You see several yellow levers labelled "CPU" etc. Flip those levers to release the cards. Release all levers except CPU.
5.) Check if GC starts. If so, turn all levers back (while the GC is OFF!) until you see the error again. The last board you did connect is the culprit.
6.) Ground yourself (earth strap to wrist).
7.) Pull each card out, blow softly over the connector, blow softly inside the GC or vacuum it. Then reseat the card softly.
I'm curious about the results.
The 3400 is a dependable workhorse (minus dirt in the electronics compartment, bad fans and oven motors and overheating of electronics).
Check if the rear fan is operating correctly and noise-free. If this fan fails the whole GC will die from overheating due to failed cooling (seen that in other labs).
