Windows 10: Computer fans turn on but computer won't start

I just got done building this PC for my sister and I can't get the Computer to turn on. When I hit the power button only the fans and cooling block for the radiator turn on.


RAM cards are working and placed properly.


Didn't see any dented cpu pins.


Reset CMOS three times.


Plugged PSU into multiple different outlets.


I haven't tested the PSU yet, planning on plugging in the 400W PSU from my computer into the motherboard of this one. it currently has a 600W from the same brand


What else should I look at?

:)

 

I unplugged my computer to soon and now it won´t start up again?

Thanks for your answer.

This solution did not solve my problem since my computer won´t power up at all. it is as if the computer is completely dead and I have tried different outlets that work for other computers but it still won´t power up.

Is my motherboard broken?

 

I unplugged my computer to soon and now it won´t start up again?

Thanks for your answer.

This solution did not solve my problem since my computer won´t power up at all. it is as if the computer is completely dead and I have tried different outlets that work for other computers but it still won´t power up.

Is my motherboard broken?

 

Computer won't start up at all

I built my first computer yesterday. I did a lot of research into building my own PC before I purchased anything and I had some guidance from someone more knowledgeable than me.

The computer was working fine yesterday, but I mistakenly put on Windows 7 32bit OS instead of 64bit so this morning I decided to reinstall the correct OS. It almost got to the end of the install when the computer switched off. Since then it hasn't worked - The machine wont turn on at all other than a green led on the motherboard .

I opened it up and unplugged and replugged in everything in case something was loose. I saw a similar topic on this forum and attempted some of the suggestions on there too.

Note: when I turn the power off and on at the wall and then try to start up the machine the processor fan spins once and a small red light on the motherboard flashs on once, though the manual doesn't indicate what that means.

The Specs are:

Coolermaster GX 750W PSU
Asus M5A97 PRO 970 Socket AM3+ 8 Channel HD Audio ATX Motherboard
AMD Phenom II X4 965 Black Edition 3.4GHz Socket AM3 6MB L3 Cache Cache 125W [w/ heat sink unit]
8GB GB (2x4GB) DDR3 2133MHz

Any help or suggestions would be greatly appreciated. Thanks!