Amiga 4000 problem!!

[redrumloa]

Last night I got an unpleasant surprise. My A4k I am doing the tower project with DIED:-( Everything was working fine, more or less, until I decided to plug in speakers. BOOM total death. Now it won't boot, or even get to the early startup menu. When I turn the computer on I get.
1)A light grey screen that doesn't change or do anything.
2)No HD or floppy activity.
3)The CD-rom acts completely dead when plugged in, won't even eject when the IDE cable is plugged in. If I unplug the IDE cable but leave power it seems normal and respons to eject.
4)Power supply test ok

I seriously doubt a coincidence, something about plugging in speakers caused the death. What blew? Does the A4k have mb fuses like the A3k? I'm going to try to dig out the old service manual, but I am hoping someone here can also give me some clues. I'd really hate to have to buy another A4k MB at this point:-(

[redrumloa]

@Vincent

I did this last night. I stripped it of everything except the A3640. NADA, i am worried :-(

[redrumloa]

bloodline wrote:
I blame the PSU.

It's a converted PC AT power supply. It was working a-ok until I plugged in speakers. I tested the PS (no load) and it seems normal except the -12V seems to be -10.46V. That should be close enough?

[redrumloa]

@voxel

Yes they are self power speakers. This A4k mb was modified by the previous owner. He/she removed the original dual rca connectors and wired in a connector to use PC speakers. It is definately the audio I plugged into. I wouldn't rule out a problem with the PC speakers, possibly energising the connector. They are el-cheapo generic PC speakers.

[redrumloa]

patrik wrote:
@redrumloa:

You dont happen to have the original A4000 PSU to try with?


/Patrik

I have a flakey one, but yeah I will test later just for completeness.

[redrumloa]

SilvrDrgn wrote:

What do you mean by plugged in speakers?  How did you plug them in?  What types of connections?[/quote]

See my other post on the speakers. The only thing I did wrong was I plugged the speakers in while the computer was on. I know this technically is a no-no, but who would have thought it really would blow something? :-?

[redrumloa]

WHOA life!!!! I got home today and unplugged EVERYTHING including mouse and keyboard. Now I am able to get the 3.1 rom requestor!! Thank god for that!

Ok.. Now to try adding one thing at a time to see what was causing me grey hairs..... Stay tuned....

[redrumloa]

*Twilight Zone music plays*

Everything including sound is working. I suspect something overheated last night :-?  The only thing I am noticing right now is a little flakeyness of the CD-ROM on the internal IDE. But the internal IDE is known to be flakey right? I am suspecting the A3640 may be flakey :-?

[redrumloa]

Ok it's definately an overheating problem of some sort. I am suspecting the 3640 is the culprit. I hope that is the case because the A3640 is only in there temporarily, I will be putting in the CSPPC tonight:-)