Troubleshooting (do you think I'm right)

So basically my friends computer stopped working one day, no reason why or anything. It kept hanging on the bios, but only when something USB was plugged in. So I figured guess the motherboard went, got a new motherboard, for some reason his dad thought it was the power supply so thats been replaced as well. 

As of right now I'm sitting on the floor with my pc and his apart to swap in know good parts and all to help me narrow it down. To preface, this after the motherboard swap the computer still won't boot, and now it won't output video. I swapped in good ram, video card, cleared the bios, removed/reinserted all power cords, no hdd plugged in so I do kill the drive and I know that it's not the hdd, so now I'm here 

The current issues are no post beep(speaker is from my system which works), no video out, no response from when turned on with no ram in the system at all, so I think it's the cpu. Would you say I'm right? I know my stuff and everything else looks right... 


it could still be the board, even if the cpu was bad I would expect the bios to give some kind of error. 


What is the cpu and motherboard you are trying to work with?

Did it work when there was no USB plugged in? Did you try change the boot settings before you replaced the MB? My guess it was trying to boot from USB. Funny things just happen sometimes, and if it was the board, I would have flashed the BIOS just to be sure. 

Well with the old MB, I couldn't get it to start with any USB devices, I used a old ps2 to get into the bios. The screen was all fuzzy when I got it to work back then too. I couldn't get it to boot with my good hard drive, His was Corrupted. I couldn't boot from a cd because it was freezing mid post with any satas plugged in, unless it was his bad hard drive? I don't understand it at all, but that's why I couldn't flash the old bios


Current specs 

8gb (tested in my build) crucial ram 

The lowest i3 2k series 

600 psu it's good 

Msi b85-g41 motherboard