Gpu post and boot problem

[kjgruber]

I have a msi z97s sli krait edition. I was originally getting a boot error. More specifically "reboot and select proper boot device" This was after I tried to change my boot device to my new ssd. I was struggling to fix it and eventually restored my bios settings to default, from within the bios. After this, my PC wouldn't post and no power was going to the keyboard and mouse. Fans were still working. I tried everything. I reset my cmos, pulled out all the hardware, and reset my cpu. I was really busy for two days and tried turning it on tonight. It posted but now I'm getting the original error message, "reboot and select proper boot device."

I fixed the problem above my re-installing windows on a thumb drive but when i plug in my GPU( rx 5700 xt red dragon) my computer won't post or power my keyboard or mouse. Any suggestions? Possible PSU problem? It's 550 watts? Can a defective gpu cause my entire computer not to post or power certain parts. The computer works fine without it.

 

EDIT: just tried a 700w power supply and it still won't work.