Z9PE-D8 WS no start after normal shutdown

Hello,
I am new in this forum also i will try to write wtih the minimum details.

I have my buld (Z9PE-D8 WS, dual E5-2670, 128Gb ram) working for almost a year, suddenly after a normal shutdown (windows 10) my system won’t start . I have several years of experience as a technician, so i start looking for the problem. At first i remove the 2nd set CPU & Ram and the System was working for an hour maybe more then it close (power off) by itself. My system was dead, every time i push the start button a click sound from the PSU then nothing (the motherboard Q codes led was off) . I try many things and the final conclusion is: when i disconnect the CPU extra power cables needed for the Xeons the system power up PSU does not click but no Q codes leds or any other reaction just silence.

any ideas… (i am serching already to replace the mobo)

Sounds like overcurrent or short circuit protection. Make sure all motherboard stand-offs are installed correctly and no wire or connector is shortened to the case.

I have a feeling the PSU is dead though.

my next move will be to disassemble the buid for that reason and try to power on without a case. The PSU power test work fine, maybe i misguided to wrong conclusions because of that. i forgot to mention that i have the Corsair AX1200i PSU

As that PSU has a monster of a 12V rail, I think we can rule out the overcurrent protection on that is what triggers (100A would make wires smoke and weld themself to random chassi parts). Check if the sata and molex cables are okay.

thank you, hope to make it work again