URGENT: PSU doesn't work only when connected to motherboard

[Samkrigs]

So I was building my pc when my PSU wouldn't turn on. So to test it i used with paper clip method and it worked. So now i am still stumped on how thesis happening. I works with a paper clip but not my motherboard. The PSU won't even turn on and i really don't know what to do please help

 

[COLGeek]

It could be your case power button header. Try swapping the reset button with the power button and attach to the power button header on the motherboard. Press the reset button. Does the system power up?

 

[Shaun o]

Yep could be as simple as that.

Another thing to think about, if you have installed the board in the case, and the main board mounting plate of the case is.
Short circuits.

This will be enough to stop a psu from powering up, if it detects any sort of + voltage hitting the grounding points of the motherboard or contact of electronic joints or components to the mounting plates.

If you have put the mounting studs on the back plate of the case for mounting and fixing the motherboard to it.
Take un screw the board again from the plate and remove it.
Now offer it up to the plate looking at the motherboard and where all the screw holes of the board are.
Double check you have not put a brass fixing standoff in the wrong place of the case for motherboard mounting and fixing.
That there is no brass ect standoff where there is no hole on the board that lines up with it and the back plate.

If you find an extra one where no hole exists to put a screw though to fix it to the back plat,e remove it quick !!!!.
Then screw the board back in.
Most of the time due to a momentary lapse in concentration and if new to building a pc it`s over looked.
But is a common fault when you find the board works out of the case but does not power up with the Psu connected to it when mounted to the mobo tray of the case ok.
Basically a short circuit. FYI nearly all new PSu`s have short circuit protection, if a voltage is found passing to ground at any point the Psu power is Isolated to prevent damage till you rectify the short circuit ok.

 

[Samkrigs]

this was an outside the case build just to test. and it isn't my power button because i can't use it because my psu won't power on while connected to my motherboard.

 

[COLGeek]

Please list your system components (make/model) so that we know what we are working with.

 

[COLGeek]

this was an outside the case build just to test. and it isn't my power button because i can't use it because my psu won't power on while connected to my motherboard.

Then how are you trying to power on? With a paper clip?

 

[Samkrigs]

No because before you try to turn the entire PC on the power supply has to be running. So i cant power or make a shortage between the 2 pin power connector if there is no power going through the motherboard. So my psu is working, but not when connected to my motherboard

 

[COLGeek]

That implies a short condition. That would implicate either the motherboard or PSU. Can you try another PSU?

 

[Dark Lord of Tech]

PSU make and model?