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[chiark]

Well, my 4000 has just died. It's a lovely machine and I want it to live again.

I removed the hard drive, plugged it into my PC and converted the drive into a hardfile image using WinUAE.

I put the drive back in the amiga (plastic shielding in place) and all works well.

I nudge the 'miggy. There's a "crack" shorting sound, a slight smell of troubled electronics, and the machine hangs. Quick check for a short, and can't see anything.

TUrn it off, turn it on in trepidation... Fans turn, drives spin, power LED dimly lights and... Black screen.

I strip the machine down it bare bones (CPU, memory, expansion riser card) and try again. Same again.

Check the PSU voltages. All look good, unfortunately. Damn.

It's dead.

I don't know what component has bitten the dust; I'm hoping it's something simple like an onboard fuse that's blown (ha)

Anyone in North England have a CPU card I can check so I can work out if it's the CPU card or motherboard that's dead?

I'm gutted. This machine is exactly how I want it, finally: OS3.9, scan doubler, piccolo SD64, warp engine, xsurf2... And it rather appears that I've killed it. I just wish I knew what has gone wrong

Any thoughts?

[tokyoracer]

That does not sound good. Have you checked is the PSU is dead? If it dies the first time it's not a good idea to try and turn it on again if it's a power related issue in-case you fry the motherboard or other expensive components.

[chiark]

I've checked the PSU voltages, and they're all as they should be.

I think something somewhere has shorted, but I can't see any obvious signs... No burn marks or the like. My guess would be that the drive carrier shorted on the back of the expansion card riser, as the insulating plastic has some tiny puncture marks in it (uh oh)

I wonder if there's any SMD fuses on the board. Worth a careful look, I think!

[tokyoracer]

Sounds like a motherboard issue. Have you checked it out compleately? I mean visually.

[chiark]

yes, however only a cursory looking over to check for shorts that are still there, signs of chip damage/blown chip...

I do have a magnifier lamp and intent to spend this evening going over the board to see if I can find a damaged track or similar. I'm also poring over the schematics.

I just wish I knew what is likely to have shorted. At first I thought (hoped) it was the PSU, but the voltages all seem right unfortunately

[Bazzaq]

Where about are you located??

[chiark]

Leeds...

Thanks for all the help & support so far. What's so, so gutting is that I think I could have prevented this by triple checking the drive...

[Bazzaq]

The lincs amiga group is having a meeting in a week or so, 2nd feb i think, im sure someone there may be able to help you out with testing it. I am hopefully going myself, if so i could bring a cpu card/psu to test.

[chiark]

I never knew they existed! Hmm, 150 mile round trip but if I can get the 4000 working it's well worth it. Thanks for the pointer, I'll get in touch.

[Bazzaq]

:-)

Its further for me to go.. liverpool to lincoln and back in 1 day.

I have only been once so far, missed the last few but hoping to go the next one.

A few of them are on here.

[chiark]

I can feel my wife's disdain already boring into me... Your doing *what* on Saturday?

Actually, damn, I probably can't get there - my wife'll be performing on-stage, and I doubt the kids (1 year old and 4 year old) will want to come with me, which leaves me rather stuffed.

[tokyoracer]

Your probably best of sending the whole thing off.

[chiark]

To whom?

[tokyoracer]

Either someone local (who you can trust) or that place in France that everyone talks about. Sorry I can't help you much on stuff like this.

Either that or wait for the next Amiga meeting them guys have.

[chiark]

ah, ok, cheers - I was actually going to send the motherboard to Anthony Hoffman prior to its death, as the audio output is dead.

From looking at the schematics, the 5v line is fused internally at 1.8A. I am hoping against hope that this fuse will be blown and, as if by magic, all my problems will be solved ;-)

Hey, I can hope can't I? :-D