No boot and no fan activity (Z87-Plus)

[TONSCHUH]

Thanks !

~edit~

Is the 8-pin (2x4-pin) PSU cable responsible for the phase that feeds the socket? May a tired PSU be coincidently the cause of the "no-cpu" like behaviour? I don't have another compatible PSU to test, but I think may be a hope!

Yes it is, May also feed power to PCI slots and memory in addition to CPU. It feeds to VRM and gets distributed further by it. If your VRM stage is for instance 4+1, 4 feed CPU and 1 would be memory power. If you suspect PSU at all, I would suggest getting a new and better one pronto, it may do damage to your parts if it dies wrong way.

I think it's the move... Mine is a 3 year old PSU intensely used in gaming rigs.

Maybe just swap it for a cheap basic one, if you have a spare one, as that should be at least maybe enough to power-on your rig.

 

[CountMike]

If it's a good, brand name PSU, not abused by pushing it to the limit, 3 years is not too old. I'm still using at least 8 year old Chieftek 400w on this machine. It's used last 2 years pretty good, almost at full power 24/7 and it still does not turn computer off if there is power failure for less than 2 seconds. Monitors shut down, lights blink, even TV set shuts down but computer keeps on running. Contrary to popular myth, PSUs don't weaken with time and usage, only electrolytic capacitors may dry out and/or get damaged, specially large ones at the final output stage. I have successfully replaced many and are still going strong. As with most electronic devices, heat is the biggest enemy.