HELP odd power anomaly

[Adamcookie22]

so i recently purchased an i5 computer change few hard drives added graphics card and a new power supply  but the odd thing is i flick on the isolator switch on the power supply powers the system on for maybe a second or 2 then shuts off and keeps repeating itself no post and no response from any power switch tried various cpus and power supplys changed memory and still the same thing any ideas 

 

[ninbura]

You've basically narrowed it down yourself, if you've tried different CPUs, power supplies, and hopefully different outlets then really the only other thing that could be causing it is the GPU or Motherboard. There could be a grounding issue with the way the board is mounted in the case or it could be something else connected to the board but I doubt it. Make sure that you unplug everything else from the board that isn't required for the motherboard to post as you test.

[aezakmi]

the PC worked before you added hard drives, graphics card and replaced the PSU, right?

[Adamcookie22]

ive removed the GPU and had the same issue and in a desperate attempt to narrow it down removed it from the case and forgot to plug the 8/4pin cpu power in and still had the same issue seems to be no matter what is in the board or where it is as soon as you turn on the power supply via the switch on the back it just wants to hit a power loop is there any possible way there could be a jumper out of place that could cause this 

 

 

[MadOverclocker]

The motherboard maybe shorting the Power. Check that there are NO screws under the motherboard. You know what, try the motherboard without the case or External GPU just this: RAM, CPU, Motherboard and PSU. Short the power button pins together. It Should start but if not well it's the motherboard.

EDIT: I meant power not signal  .

[Adamcookie22]

i dont even need to short the power button pins as soon as i apply power to the power suppy it powers on in the loop thats all whats got me stumped 

[paddy-stone]

Reset CMOS.

[Adamcookie22]

as the system sits it is on the motheboard box no GPU 1 memory modual CPU and power supply and still powers on as soon as you flick the switch for the power supply

 

[aezakmi]

1 minute ago, Adamcookie22 said:

as the system sits it is on the motheboard box no GPU 1 memory modual CPU and power supply and still powers on as soon as you flick the switch for the power supply

check if the CMOS pins need to be shorted in order to start

[Adamcookie22]

okay so i found the issue there was 2 pins hidden next to the vrms and it said about MEBX-Reset was shorting together