How to troubleshhot an A4000 Rev. D

OK, so I have this A4000 Rev. D motherboard, that is optically in a very good shape, coin battery etc. The minor problem however is, that it seems to be dead.:wooha:

The motherboard is loose, so far I have plugged in an A4000 PSU, connected a CPU card, connected a monitor and tried to turn it on. Result: black screen..

So I was wondering if RAM has to be installed to get to the KS screen? Or maybe the daughterboard has to be plugged in?

Do you guys have any advice how to troubleshoot this? Just to roughly pinpoint the trouble (heh quite an oxymoron) and find out if there is hope to repair it..:help:

No RAM is needed to boot. And the daugtherboard shouldn't be needed either.
But if you have a daugtherboard nearby it wouldn't hurt putting it in.

Why a CPU-card?? The motherboard (rev.D) has a CPU onboard (030) so that is not needed... maybe that's the problem? 2x030 ;)

Next thing I would try is to re-seat all socketed chips...

First, check each of the capacitors. If it's this, then change them with good reliable capacitors, not with low life model.
Try with another A4000 PSU & CPU card.

Check if keyboard led comes on on power up, if not, big, yellow fuse is snapped or faulty, board is dead then

Afaik it won't boot without the daughterboard.

Never had rev D but rev B works fine without daughter board

Quote:

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Originally Posted by JLPedro

Afaik it won't boot without the daughterboard.

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@drbrain: This motherboard doesnt have a CPU nor FPU on-board (new pic added), also there is only one socketed chip which is a super-buster 11, this was removed and re-inserted with no change in the symptoms

@LTAC: The CPU board and PSU is coming from a working A4000 system. How to check/test the capacitors?

@bebek: Since its loose I cant see the leds but I did measure 5V on the PINs of key and pwr (see picture) could this be a good sign?

@JLPedro: I only had a Rev B daughter board which I tried but no success..

Visual inspection. But anyway, the life of the capacitors on A1200/A4000 is limited. So to change quickly.

There seems to be no crystals in U104 (50.000MHz) and U154 (28.37516MHz)... that's probably why it won't boot.
Those are needed for the timings(chipset, cpu) etc on the motherboard...

Quote:

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Originally Posted by drbrain

There seems to be no crystals in U104 (50.000MHz) and U154 (28.37516MHz)... that's probably why it won't boot.
Those are needed for the timings(chipset, cpu) etc on the motherboard...

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I Agree :thumbsup: