Tuesday, March 18, 2014

Zombie Amigalypse

First up is a B2000, rev 4.1 motherboard. Symptoms are black screen. When pushed on MB around Agnus, ROM, 68k, the Amiga either boots or shows a green screen.

Initial diagnose: Faulty Agnus(socket), bad PCB traces.

Swapping the Agnus did not result in an improvement. Looking at the board resulted in a couple of observations:

1) The board has had a 1 MB Agnus modification
2) Someone didn't really understand those instructions and also pulled pin 41 of the Agnus socket (only needed on A500 models).
3) There was a big scratch running through 2 traces between ROM and 68k.

I couldn't really test the continuity of these traces, so I just scraped, cleaned and retinned them to see if that worked. If so, I would solder a copper wire on top of it and recoat it.

Here also no improvement on the symptoms.

Then I went ahead to replace the Agnus socket. Too bad I seemed to have run out of them, so i'm waiting for replacements.

Hopefully some better news next time.


  1. How did it go ? I might order an Amiga B2000 with the same symptom and would like to hear how it went :)

  2. I just bought a new motherboard for 10 Euros. I think there is a crack somewhere near the CHIP RAM chips, but in the end, I could not find it.