No boot, blank screen help?

[lookerup]

My cousins computer psu had a spike in voltage on his computer about 2 weeks ago. I asked him to get a XFX 750w psu(there was a $20 rebate). After installation finished, still same situation. Motherboard was also switch out with his old one. Both did not let out a beep. No visuals from graphic card( i will test with a old 9800gt card that my friend left around). Can not tell because i don't know if i have a valid board to use. Everything else seem to works fine. I'm having problem isolating the problem. I can't have my cousin spend money recklessly either. I told him to change power cords and surge protector strips to eliminate other source of problem. Fans are moving and they are all powered up from the board. Please help me to isolate issue so I know what to do next. Thank you in advance.

System;
CPU: Amd phenom II x6 3.0 1075t ghz
Motherboard: Asus M5A97
RAM: G.SKILL RipJAWS ddr3 1333ghz
GPU: Radeon HD 7850
PSU: XFX 750w

HDD:irrelevant
CASE:irrelevant
SSD:N/A
Optical:irrelevant

Things i have done is :
switch motherboards.
switch power supply
reset CMOS

I do not have a volt meter, unfortunately i can not measure anything.

 

[hillmanant]

Make sure all connections are made in the following some forget the cpu 4 pin power. Try unplugging everything from the motherboard but the cpu and cpu heatsink fan see if you get the constant long no memory beep, If you get that install the memory listen for the one long and two or three short no video card beeps. Then add the video card and monitor. If you get no beeps at any point whatever component installed up to the point with no beep could be the issue. If you get nothing at the start and you've tried another motherboard already it probably fried the CPU.

 

[hillmanant]

What did you find out?

 

[lookerup]

Lmao i didn't put the pin back on the board when resetting CMOS. This was after installation of new power supply. Everything is fine now. Resetting CMOS should ensure nothing in bios was touched, should be no voltage spike anytime soon. Thanks dude.