What brand of PSU? It makes a huge
Hi I tested the PSU, in particular the 4 pin atx plug with a multimeter and Im getting a consisitent 12.14 out of each pin?
Is that with the cable plugged into the motherboard? If not, there's little load on it. And the reason you get the same voltage out of each pin is that the two lines are wired in parallel back at the PSU.
I have changed the psu to known working ones but to no difference.
Of similar capacity?
Why does the pc stop cycling on and off when the 4 pin atx plug is disconnected?
With the 4 pin plug removed, you have no power going to the CPU, so the system isn't even trying to start.