New PC build - blinking underscore black screen

[pegliposome]

Hi y'all, I just finished assembling the components for a friend's PC. When I power it on it immediately goes to a black screen and blinking underscore in the top left hand corner. I don't get to see the BIOS or motherboard logo. What makes matters worse is that keyboards/mice/USB do not work. Upon plugging in my keyboard, the lights on the keyboard flash for less than a second before disappearing. What are my options?Thanks

This is what the mobo looks like as the underscore blinks: https://i.imgur.com/L5UE5wK.jpg

Parts list:

i5-7600k

Hyper 212 LED

MSI Z270 Gaming M5

Corsair Vengeance LPX 16GB DDR4-3000

Samsung 750 EVO 250gb

WD Caviar Blue 1 TB

Asus GTX 1060 3gb

Corsair RMx 650w 80 Gold Certified Modular PSU

 

[alexoiu]

Hi, Have you tried clearing the CMOS (unplug the power cord and remove the CMOS battery for a minute)?

 

[pegliposome]

Hi, Have you tried clearing the CMOS (unplug the power cord and remove the CMOS battery for a minute)?

I did that, proceeded to turn it on, and the underscore was replaced by a bunch of haphazard letters on the screen. After rebooting several times henceforth, it went back to the underscore. It's giving me a postcode of 62, therefore it might be a bios/cpu incompatibility

 

[alexoiu]

It seems so, although it shouldn't. I'd RMA the board.

 

[pegliposome]

It seems so, although it shouldn't. I'd RMA the board.

RMA's take too long so I'd like to exhaust all of my options before heading in that direction. Any other ideas?

Ty