I think PSU turning on then immediately off generally means an overload/short somewhere. If the PSU stays on when there's no CPU fitted then the problem might be with the CPU. Have you got any other's that you can try?

Unfortunately no, I had a few, but probably threw them away as I've just recently got into retro gaming. Will try to find one.

On my Epox 8KTA3+ Pro 'FF' on the integrated POST code card means everything is working and the system is ready to boot an OS.
If you take out the CPU you should only get bogus POST codes afaik. Maybe it's hard coded to display 'FF' when it only gets power?
Like snufkin said an immediately turning off / clicking PSU points to a short circuit, if it doesn't occur when taking out the CPU I'd also assume the CPU is bad. You should be able to find some Duron for next to nothing if you want to investigate further.

Good luck!😃

I read somewhere that FF is either all is good or everything is f*ed 😁 Will get a new cpu and test it, its a good board.

Non related, does it support agp 2x? I have a Kyro gpu on its way and just remembered it only supports 3.3v slots.

Here's what's in my manual (mobo EPoX MF570 SLI):

Post some clear pictures of the motherboard out of the case. Sometimes people can spot problem areas if there's something physically wrong with it.

There are many options... Pictures can help as mentioned above.
First I'd suspect either capacitor and/or MOSFET shortage problem. Motherboards from that era have very often bloated or dried capacitors. While ago I replaced caps to my EP-8RDA3+.
Second, have you another CPU? Before trying with another CPU it's better measure using multimeter MOSFETS are not shorted. (done that - not a good idea)

sirotkaslo wrote on 2021-05-20, 12:36:

I read somewhere that FF is either all is good or everything is f*ed 😁 Will get a new cpu and test it, its a good board.

So it is Full Function as well as Fatal Fault. Nice!😄

Non related, does it support agp 2x? I have a Kyro gpu on its way and just remembered it only supports 3.3v slots.

I think some Kyro boards are configured to identify as 3.3V signalling only while the graphics chip actually supports 1.5V signalling as well.

Your Epox board does not support 3.3V signalling afaik so the card may trigger a safety mechanism that keeps the system from starting. If that's all true there's an easy mod for your Kyro to make it identify itself as 1.5V signalling compatible.

8RDAs were known for bad caps. If you see any leaking or bulged capacitors, that's probably the problem.

Got an inkling that was one of the board that there were droop mods for, so possibly kind of marginal in the power department from the factory.

Hi,
sorry for the late reply, finishing my house and am currently really busy with it. Going to pick up an athlon 2400 today along with some other retro things and will try to make it work, if not, will post the mobo here.

Doornkaat wrote on 2021-05-20, 21:12:

I think some Kyro boards are configured to identify as 3.3V signalling only while the graphics chip actually supports 1.5V signalling as well.

Your Epox board does not support 3.3V signalling afaik so the card may trigger a safety mechanism that keeps the system from starting. If that's all true there's an easy mod for your Kyro to make it identify itself as 1.5V signalling compatible.

I found a mod to make it work with agp 4x, kyro only arrived yesterday so I haven't had the chance to try it out yet.

Unfortunately new cpu didn't help, I believe the 7600gs destroyed this board, because I tried that gpu in another pc and now that one is also dead.

You mean you blew your mobo with bad graphics?

I got this mobo with the gpu and it wasnt working. Yesterday tried the gpu that came with this pc in another one and now that mobo is also dead, so yeah, I guess you can say I did.