Computer continually restarts without reaching BIOS

AStoutTrout

Prominent
Aug 6, 2017
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This is my first time building a computer and I had it working for a little while before the motherboard died, and now I've moved everything to a new motherboard, and now the computer powers on (lights on the motherboard come on and the fans spin) but a few seconds later it powers down then continues turning on for a couple seconds and then momentarily turning off until I cut the power. I've tried removing everything but the cpu, mobo, and psu, as well as testing the ram individually in each slot, and resetting the CMOS both by shorting the clear CMOS pins and removing the battery. I suspect it's either due to another defective motherboard, since it does the same thing without the cpu, or maybe my psu just doesn't provide enough power. Is there anything other I could do (note I don't have any spare parts as this is my first build)? Or do I need to replace something?

Specs:
CPU: i5-7500
Motherboard: Gigabyte B250M-D3SH
RAM: 2x4G Team DDR4 2400Mhz
PSU: 450W Corsair SF
SSD: Adata SU800 128G m.2 (not plugged in)
Graphics Card: Gigabyte GTX 1070 OC (not plugged in)
 


Yeah, that's the operating system that I have, but it doesn't seem to make a difference whether I have the SSD plugged in or not