CPU Fan turns on for half a second and then stops.

[joeyturner123]

Hi all,
Just built a PC and every time i power it on, the cpu fan turns on for about half a second and then stops (I assume the system is shutting down too.). Also, if i connect case fans to the PSU they also spin for half a second and stop.

All parts are brand new from Amazon/Ebuyer, and are as follows:
Mobo: Gigabyte GA-78LMT-USB3 (Rev 6)
CPU: AMD FX4300 Black Edition (with stock cooler)
Memory: HyperX Fury 8GB DDR3 1600MHz
PSU: Corsair VS550
Case: AvP EL03W Viper Mini Tower
(Plus a Kingston SSDnow300 120GB + TP Link Network Adapter + Fractal Design R3 120mm Case Fan)

I have tried:
- Putting the ram in each of the 4 slots seperately
- Disconnecting all the power cables and putting them back in
-Taking out and putting in again the CPU
-Disconnecting all cables except power switch and both ATX Power Cables
-Taking out the TP Link adapter (it's standard PCI)
-Disconnecting all case fans
-Taking out motherboard battery for 1 min and then putting back in again
- Connecting to a monitor- getting a "No Signal" which means PC must be turning off after the fan spins for half a second.

Anything else i can do?

Thanks in advance.

UPDATE: PSU Fan doesn't spin AT ALL. Could this mean a faulty PSU?

 

[alexoiu]

Hi, I suggest testing the board outside the case to rule out a short.

 

[joeyturner123]

Hi, I suggest testing the board outside the case to rule out a short.

It's always something this simple. Thank you so, so much

 

[alexoiu]

You're welcome.