PC won't boot with 8 pin CPU power plugged in.

[mark112399]

Just finished building a new PC, wouldn't boot when motherboard was in the case, thought it might be a standoff shorting the board, so I took it out and tried to boot it on a cardboard box. The heatsink fan, PSU fan, and GPU fan all spin for about 2 seconds and the LEDs on the motherboard light up and then die. Unplugged the 8 pin CPU power and the fans stay spinning and the LEDs stay on but no POST noises or anything else happens. Have tried 2 different CPU's, a different PSU, and a different motherboard, same issue. Idk what to do.

Specs:
Mobo: MSI B250M PRO-VD
CPU: Intel Pentium G5400
GPU: ZOTAC GTX 1050 TI
PSU: EVGA 500W
RAM: Ballistix sport (1 8gb stick) DDR4

Any suggestions? Thanks in advance.

 

[bignastyid]

The G5400 is 8th gen(coffee lake) and like every other 8th gen Intel cpu it is only compatible with the 300 series boards.