USB Ports, Screen not working after overheat

[DecisionGaming]

Hi! I was playing League of Legends and suddently my PC turned off, black screen, one-shot. Now, I can turn on my PC, but nothing shows up on the screen (still black) and there are no power going thru my screen and my keyboard/mouse from the USB Ports (I know since they usually illuminate green Razer). HP logo lights up, fans are working Max and my graphic card's fan is working too and the power supply runs.

I tend to say it was due to an overheat, since my graphic card was heating a bit, but I feel like the problem comes from the power I don't get from the MoBo, to my USB ports, because when I turn on the PC, the fans are set to Max, just like before the overheat. (By the noise, because I don't see anything on the screen, I can't get on it and I don't know if it really boots, I have no green or red lights showing)

What to do? I can't get on my PC?

Specs: Windows 7
HP pavilion elite
i7
nividia geforce gtx 480
12 gb ram
750w power supply
1.5 T storage

I WILL ANSWER BACK FAST !
Thanks!

 

[norsestar]

Offhand, I'd guess the PSU has failed. What make and model is it? Can you borrow another PSU to test with?

 

[DecisionGaming]

Offhand, I'd guess the PSU has failed. What make and model is it? Can you borrow another PSU to test with?

720W Peak - High Power (Brand) - Model: HP-600-G14S

And yes tommorrow when i'll wake up i'll test with my other power supply: 300W - LiteOn - PS-5301-08HA

Thank you very much for answering, i was so bored today with no PC, i need to locate the problem, and fast!

 

[DecisionGaming]

Offhand, I'd guess the PSU has failed. What make and model is it? Can you borrow another PSU to test with?

Ok so I tested with the other power supply 300w and it needed more wiring for my graphic card so I couldnt really try, but i did a test for my 750w power supply with a pin and the fan works, so i don't think its my psu.

With the 300w fan I tried to plug usb keyboard and mouse, without pluging the gpu to the power supply (beeping noises obviously) just to test if i could power those usbs and it didnt work.. what can i do.. i really dont know whats the problem here HELP 🙁

 

[norsestar]

If you do the paperclip test and the fan doesn't spin up then the PSU is dead, but a spinning fan doesn't mean clean power under load. I'd still want to test with a known-good PSU strong enough to power the video card.

My next step would be to breadboard it: http://www.tomshardware.com/faq/id-1753671/bench-troubleshooting.html . Does it normally give the single short "everything's okay" beep when it boots? If so, strip it down to just motherboard/CPU/cooler (out of the case) plus PSU and it should give a series of beeps since it's got no RAM.