Computer wont turn on...

[Max123]

Well it does for about 0.5 seconds and then turns off again, then 5 seconds later it trys to power up and it turns off.

I've managed to find out it's when the 8-pin or 4-pin power connecter is plugged in to the motherboard, it just dosn't want to power up. Any ideas?

Motherboard: a-bit IP35-E
Power Supply: Corsair HX 520W

Thanks.

 

[misterPK]

OK, so with the CPU power connector in it doesnt power up at all? No whirring fans or flashing lights?

And with it not plugged in it does power up, but not properly. Well that bit sounds exactly like how it should behave if the CPU connector wasnt plugged in, so thats no help!

Is this a new build or one you've had going for a while?
Is there a speaker/buzzer on this type of motherboard or one in your case connected up to it? If so, does this beep at all when you power it up?

PK!

 

[Max123]

It powers up without the 8 or 4 pin connector in, but when I plug them in the cpu fan powers up and then pretty much instantly powers down again and repeats this every 5 seconds(ish)

I've just replaced the motherboard after the previous one was faulty, I had it running fine before hand with the old motherboard for about 2 months.