I got some spare time and I decided to check by myself the pinout of the PSU just by following the tracks in the PCB and doing the math behind the componentes. The machine is a Schneider Euro pc 80286 AT system 40. I´ll share what i´ve discovered in case someone needs the info.

The Pinout is as Follow :

Blue -> GND -> Black on ATX
Yellow -> +5V -> Red on ATX
Orange -> +12V -> Yellow on ATX
Brown -> Ok PSU/ +5V -> Gray on ATX
Red and white -> This two are the ones that go into the relay and out of the relay into the NCV2901. They can be left as is, as you have to bridge black and green on the ATX PSU in order to turn on the PC,

step #1 check the fuse
get out a dmm, and power the unit, do ANY of the voltages work?
then things get kinda hairy from there, but thats a start

luckybob wrote:

step #1 check the fuse
get out a dmm, and power the unit, do ANY of the voltages work?
then things get kinda hairy from there, but thats a start

The fuse was not damaged, no current/Volts is shown in the dmm display when testing the pins and there is no visible damage either. I think that ill stop tinkering with it as it can be quite dangerous and I´ve succesfully adapted an ATX PSU after figuring out the pinout as you can see in the images.

It may be that it has worn out of age, who knows 😊 .

Some ancient PSUs just don't start if there is no load. So it might be OK after all.
If you need to test it use a dummy load. I had to put 2 HDDs on one AT PSU before it gave any sane voltages out.