VOGONS

SK8V to fix, help appreciated

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First post, by Mamba

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Hello all,

After a search of decades I was able to find a SK8V.
I am trying to restore it as it won’t boot (but it did, I saw it).
My debug card showed codes and every day I was able to go further with the boot process.
Now suddenly the debug code display - - so nothing AND I hear an electrical high freq squeak from the VRM portion I think.

When I unplug the 12v plug, there is no sound.

So I think something is going wrong with VRM, chokes, capacitors (?).

I uploaded a pair of pics, maybe your eagle eyes can spot something I cannot see.

Reply 1 of 3, by Matth79

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Badcaps I'll bet, the ones closest to the CPU heatsink are probably cooked, even if they don't look obviously bad, replace with polymers if possible, otherwise low ESR electrolytics

Reply 2 of 3, by paradigital

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My guess is on caps also.

Has the board been cleaned at all? In the pictures the MOSFETs and the board seems covered in something, which could be nommy cap juice if it's not an attempt to clean.

Reply 3 of 3, by Mamba

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paradigital wrote on 2025-05-24, 14:50:

My guess is on caps also.

Has the board been cleaned at all? In the pictures the MOSFETs and the board seems covered in something, which could be nommy cap juice if it's not an attempt to clean.

Yes,
Even if I do not see bulging caps, after 20 years they could be drained.
The thing you see is Isopropyl, I just cleaned it.

It is unfortunate that this noise happened under my hands.

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