I assume the graphics card doesn´t need -5V?

AT or ATX PSU? Tried a different PSU?

The rest of the components are fine. PSU serves 4.6V-4.8V, not ideal, but ok.

Did you check (Tantalum) Capacitors in -5V Path ?

Not yet, just not sure if -5V plays a role for VGA, does it ?

pshipkov wrote on 2023-07-10, 22:55:

Not yet, just not sure if -5V plays a role for VGA, does it ?

-5V is not used for *anything* except old soundcards and maybe obscure industrial interfaced

Thanks.

It's original purpose was a bias voltage for ancient 4116 DRAM on the first model of 5150. Almost nothing used it thereafter but it nevertheless stuck in the spec until ATX was revised in the early 2000s

Not only that, some sound cards and true hard core serial cards.

Cheers,

Thanks for the clarification. I will keep looking then for other issues.

I would trace where that positive voltage is coming from, can be blown onboard serial transceiver