Dead motherboard

[BOFH]

It's embarrassing that I have to ask for help, but fresh insight might be the clue.

Until Saturday, I had two P-IIIs running - one is an Abit VP-6, which can handle two CPUs, and the other an old Biostar. I bought a modern motherboard and whatsits, removed the VP-6 from its case and put the newfangled bits in. No problem.

I removed the Biostar (single CPU) MB from its case and inserted the VP-6 and a new power supply, plus the RAM from the Biostar. Hmm, no boot. Since then, I have tried what I believe to have been every possible permutation - CPU from Biostar, only one stick of RAM (and changing those from time to time) and a different VGA card. This is wearing thin after four days, so - if I understand correctly, for a boot, all I should need is RAM, a CPU and a video card.

I thought I would test the power supplies/CPUs/RAM so I tried booting the Biostar - it's silent too :sad:

I hope someone can put hs hand up and say 'did you think of x?'. I've been doing this for twenty years and I'm bloody stumped. Any suggestions are welcome. At my disposal, I have:
2 power supplies (both working on Saturday)
2 CPUs ditto
4 memory modules ditto
2 VGA cards ditto

I would be most grateful for any advice.

BOFH

[rickity]

Had something a bit similair not so long ago, found to be a short between the motherboard and the case, I hadnt used a piller in one corner, and inadvertantly screwed the motherboard tight down to the case, fortunatly no lasting damage. You could try running all the kit outside the case.
Rickity

[Flightsimman]

Hello there,

Have you tried another item on the same power point ???

If that works fine I suggest that you remove both motherboards from the PC cases, place them on some "anti-static, non-metal" material and also remove the power supplies from the cases, then try and run them on a bench.

If this fails I would turn to the multi-meter to see where your short is.

Best of luck.

[BOFH]

I wish I could say that's fixed it, but it hasn't, as I've already tried the old take the MB out trick, different power outlet trick, putting the MB in the freezer overnight trick (there was a cold solder joint on the MB - it cost me two week's pay at the time to have it fixed!).

All capacitors have been inspected for leaking and the BIOS chips have been re-seated.

I wanted to thank you for your advice though - it could well benefit someone else having trouble.

Mext step - test the power supplies - in the bath. :mad:

BOFH

[Saab Dastard]

Clutching at straws I know - there isn't some form of safety cut-out that stops you powering up with the case open?

I've actually come across a (very) few of those - just need to identify and bypass / fool it.

[Flightsimman]

Mext step - test the power supplies - in the bath. :mad:
BOFH



Hahahah....Don't do that mate...

Why don't you take your power supplies to your local PC shop and have them tested ??

Worth a shot...

:{

[BOFH]

Hi Saab,

not that I have ever seen with Intel stuff (the 240V switch on the front died out in the early '90s), but your point is relevant, as you'll see.

I am pleased to say that the fault has been found. Lessee, I had a redundant component for everything - EXCEPT - the power switch on the case! I tested it for continuity, saw none, and repaired it.

The trusty old duallie is running quite nicely now and it's a relief not to lose the 600GB RAID0 drive (which was backed up, but would have been a pain to restore).

Cheers again to everyone who encouraged me not to give up.

BOFH