System completely unresponsive

[seph88]

Hi everyone,

 

I have an i7860 OC'd @ 3.8ghz wiith a CoolIT A.L.C. liquid cooler, 8gb Corsair DDR3 1600mhz, 1tb HDD 7200rm, 2 x MIS GTX 470's in SLI and a Cooler Master 1100w psu.

 

Over the last month the PC's been having an issue whereby when I first turn it on, after about 2 minutes the screen just goes black and the system becomes unresponsive. Once I restarted it, the machine ran perfectly fine.

 

Anyway, Today, I packed the machine up and took it to my folks as i'm on dog sitting duty for the next week and when I arrived I connected it up to the television in the living room and, apart from the usual black screen crash, it worked fine. However, two hours ago, I started it up again and...nothing. It sounded like it was starting up as usual (except no beep from the motherboard). I could hear and feel all the cooling, gpu and psu fans spinning and the HDD platters but the screen just wouldn't come on at all or register that the PC was even connected. I tried taking the GPU, RAM and HDD out and resetting/connecting them. Tried putting only 1 stick of ram back in and one GPU but it still just does the same thing. I've used different power points and a different moniter but the computer just seems completely brain dead.

 

If anyone has any suggestions, they would be greatly appreciated.

[Plastic Nev]

Hi and welcome to Extreme Tech Support - Free PC Help.

Although fans and other things sound like they are starting up, the fact you no longer get any POST beep is a bit worrying that something has died on the motherboard, or the PSU. The only way forward would be a try of another PSU first, if no go then it may be the mother board.

However there could also just be something amiss with other hardware.

Try this, disconnect everything from the mother board except the power molex connector from the PSU, and the wires going to the start button, then turn the power back on, you should hopefully then get one or more beeps. Power off again then connect something, power back and try again until the beeps don't sound, whatever it is that was last connected will be the problem.

If no beep with only power connected, it may be the board or the PSU.

Nev.

[seph88]

Hi and welcome to Extreme Tech Support - Free PC Help.

Although fans and other things sound like they are starting up, the fact you no longer get any POST beep is a bit worrying that something has died on the motherboard, or the PSU. The only way forward would be a try of another PSU first, if no go then it may be the mother board.

However there could also just be something amiss with other hardware.

Try this, disconnect everything from the mother board except the power molex connector from the PSU, and the wires going to the start button, then turn the power back on, you should hopefully then get one or more beeps. Power off again then connect something, power back and try again until the beeps don't sound, whatever it is that was last connected will be the problem.

If no beep with only power connected, it may be the board or the PSU.

Nev.

 

Hi thanks for the fast response.

 

I tried as you said and unplugged the PSU from everything but the motherboard and still there was no beep. I actually have a spare motherboard and Q6600 at home so in the morning i'll fetch it and plug it into the PSU and, if it beeps, then i'll know it's the motherboard and, if not then surely it must be the PSU?

[Plastic Nev]

Hi, I would be looking to swap or at least do a full test on the power supply unit first, after all it is the easiest to swap out.

Considering the PSU has several different voltage outputs, it is common for just one output to fail and not the rest, hence why fans run but nothing else will.

Nev.