Computer not booting to POST

[Gasur]

I bought a new motherboard & CPU for my little brother, so he had a newer computer he could play on, however it refuses to boot properly.

Everything is the same as the previous computer, besides the motherboard, RAM and the CPU (listed below).
I've built quite a few computers myself, so I took time and precautions such as anti-static wristband etc.
However, when I was finished and plugged it all back together it booted (all fans spun up), but the screen never showed anything. I tried using the onboard GPU that the CPU has & my own 660, neither worked. Just to test that it wasn't the screen, I also switched them & used both HDMI & VGA to test that as well.
Just to make sure that the RAM wasn't faulty in any way, I plugged it into my own computer (which uses the exact same RAM) and it worked just fine, even with 30 minutes of "heavy" usage.

Not sure what else could be wrong, maybe a faulty CPU/Motherboard?

CPU: Intel Celeron G1620.
Motherboard: Zotac H61MAT-A-E (I know, I was on a really really tight budget).
RAM: Corsair XMS3 1x4GB 1600MHz (http://www.amazon.co.uk/gp/product/B0045HXQV4)

Edit: I also tried switching the RAM from slot1 to slot 2 (total there is two), as well as removing the SATA cables, neither worked.

 

[rdizz81]

when you built the computer did you connect the PSU to the 8pin connector close to the CPU? did you plug in the video card not to the slot but did you add the 6pin connector from the PSU? just some simple things to check before going any further and giving you a bigger headache lol

Are you getting any beeps or error messages?

 

[Gasur]

Accidentially clicked the wrong button in my email. Also, I did double check all of that, CPU connecter is there, GPU connecter is there too, however it isn't technically needed, ATX connecter as well. I even tried unplugging them and plugging them back in, no use.
Also, no error messages what so ever. It sounds exactly just like a computer booting up, but nothing happens on the screen. Not sure if this has something to do with it. But when I turn it on, the Intel stock fan (CPU) spins a round or so, then stops for a second then freaks out and spins to max speed for about 5 or so seconds.