Green screen of death

[doyle86]

Hi every one,
   I have pulled my A4000D out of the garage after 5 years of collecting dust.  When I firsst booted it up I got a flashing green screen.  I looked on this forum and found the green screen indicates a chip ram problem.  I wiggled the simms and got it to boot.  I reinstalled WB3.1 and  it worked fine.  I left it on while I looked for a cdrom driver and when I came back the computer had froze.  I turned the power off, waited, then turned it back on and I was back to the green screen.  I have removed the MB, cleaned every thing I could, paying close attention to the simm area.  I even took the opportunity to have new capacitors put on the 3640 card.  Still have the green screen.  I've tried moving simms around without luck.  I only have the one 2mb simm for the chip ram slot.  The other simms are 4mb.  Any ideas?  I have a revision B motherboad.

 Thanks in advance for any help.

[doyle86]

Does it have to be double sided? Is that why the other simms used for fast ram won't work?

Thank you.

[doyle86]

Thank you.  I seem to only have single sided simms laying around.  I will get hold of the right simm and give it a try.

[doyle86]

One last question,
    Can I use a EDO simm for chip ram?  I've found info that says the A4000 does not support EDO.  I'm wondering if that means the MoBo just doesn't use the EDO capability.

Thanks.

[doyle86]

Hi folks,
     I got a hold of an 8mb double sided simm and tried to use it.  I got the same result.....green screen.  I have the right 2mb simm coming from amigakit.  I'll try that then failing that I would like some more advice. I've read something about a bad power supply being the problem or maybe even the Agnus chip.  I'll keep you posted.

Thanks

[doyle86]

I took a good hard look with a magnifying glass and the traces look ok.  I'm going to take an ohme meter and check for continuity in the traces.  Also,  I guess it's the Alice chip that handles the chip ram.  I'll keep poking around and let you know what I find.

[doyle86]

I found a chip at U706 that looks like the insides are coming out.  There is this gray stuff all over the pins.  This is on my A4000.  Any clue as to what the chip there does?