Question PSU Problem?

[DilawU]

My PSU won't boot my pc but boots other pc that is more demanding than mine, and the PSU from the demanding pc boots both PCs. What could be the issue?
Edit1: I tried 3 PSUs , same psu for 2 computers, one with fx-8300(mine) one from like 2007(mine) and one with fx 6300.
Only 1 psu boots all 3, and all 3 PSUs boots only the fx 6300 PC.

 

[Roland Of Gilead]

Is this a trick question? A conundrum of sorts!? Just kidding.

There is a lot of info there, but also not enough.

Can you list all three systems? All three PSU's? In detail.

It could be a multitude of things, depending what hardware is in each system, what PSU's you are using and how old they are. It could even be something simple like faulty cables on one of the PSU's if they are modular/semi or not modular at all.

Soooo many possibilities!

 

[DilawU]

System booted by all 3 PSUs : ASRock 970 PRO3 R2.0 , FX-6300 , GTX 1060 6GB , Hyper 212 EVO , Zalman Z3 Plus.
System booted only by 1 PSU ( PSU "Sirtec High Power Plus 500W" of the system booted by all 3 ) : Asus M5A78L-M LX3 , FX-8300 , GT-730 or something like that, it doesn't matter anyways because i only pluged in mobo.At all 3 of them.
And the last system is a very old system, don't really know the specs.