Some older gear is cheap but here no make, model to work with.
Troubleshooting down past CPU or board requires us to have spares. That's where a shop wins. But since a shop fee runs about 150 here I usually just replace both CPU and mainboard to make sure I got it.
I think I've narrowed down the possibilites to 2 parts: CPU or mobo.
I really hope it's not the CPU because that would be expensive.
So this is what I think can help you answer me : if I don't plug the 2x4 CPU pin to the mobo that makes no difference in the actual problem which is that every fan starts spinning hdd too and then just nothing. No beep, no BIOS screen like no screen whatsoever. I've tried the RAMs the gpu but that doesn't make a difference.
Also I have a button to clear CMOS and that is the only button to restart the system, the power button and the reset button doesn't do a thing.
I'd appreciate any help from you guys.