PC won't switch on(URGENT)

[Spike]

Today I went with a friend to buy a computer by components. Then we went to his home to build it. I built as I always have done, but it doesn't switch on.

The components are good ones, I mean, there's no cheap parts on it, the important components are:

PSU: NOX APEX 700 W modular
Processor: Intel Core 2 Quad Q9400
MOBO: GB-EP45-DS3LR
Graphics Card: 9800 GTX+

Power LED switches on for a second then it turns off. And the most weird thing is, his monitor (which worked fine this morning) has stoped working after the first try.

I've thought, could it be PSU related, overvoltaging the PC and destroying the monitor? As far as I know PSU have overvoltage protection, and the PSU model is a very good one. I don't really understand what's happening, it's the first time this happens, and seems my friend comes from having a good monitor and a new PC to having destroyed components and monitor.

[zombie@computer]

make sure you wired the switch correctly. Eg, wiring reset button with power pins and vice versa
if that aint it, rip out all peripherals, memory, gpu, hdd's, the works, so you start blank with psu, mobo, cpu. Should give you beep codes. Then keep building stuff in untill you find the culprit.

if theres no beep codes even then, its either wiring, psu or mobo.

[MayheM]

Is the PC making any tones as it tries to start? I had a similar issue when i tried to use a cpu that was not compatible with my motherboard. Are you sure the CPU you have will work with that board? Other then that, check to see if everything is seated properly. Not sure what else to tell you...

[poisonic]

first guess your psu is DEAD because of the heavy load i think 1000 watt would be better

[poisonic]

and is the psu connected to the video card vid cards realy like power

my new videocard that i wanna buy asks 450 watt at full load gtx295

[Spike]

@zombie: I tried switching them and it didn't work. I removed the hard drives and it doesn't work. Problem is fans doesn't even spin, and components seems to not start working. I think it's probably a PSU problem.

@Mayhem: No, it just switches on the power LED for a second then it stops working, no components seems to start doing their job. We bought the components on a trusted shop, I don't think they would sell us non compatible stuff, and components are quite popular.

@poisonic: I don't think so, I have a much heavier PC with a 580 W PSU and it works like a charm. (H4870, Silent Knight II cooler, Q6600, 3 RAM fans, 4 GB RAM DDR2 1066 MHz, 2 Hard drives, 1 DVD, sound card, wireless card).

Also, the thing that really anoys me is why would the monitor stop working after beeing conected to the PC? We have connected the monitor to another PC and it won't work (the monitor).

[Jasard]

No ways its the wattage of the PSU

[vcool]

I second rewKe, I got my 520W Corsair steadily pushing the once-hungry 8800 GTS at an overlcok, as well as a Q6600 at 3.28 GHz.

Looks like a PSU problem to me. There's always a broken product, even if made by top-level companies. change the PSU and see whathappens. I am sure the store will accept a return.

[1447]

Your problem sounds a lot like one I had some time ago. I made a thread about it back then, maybe you can find something useful in there:
viewtopic.php?f=21&t=26325

[zombie@computer]

I repeat, did you check the wiring of your power switch? One second on and off is exactly the time a reset button powers on and off a pc for resetting it

[Spike]

Yeah it was the PSU, we changed it to the old one and PC works, so now it's time to see if the shop is going to repair the monitor too...

[poisonic]

lol so i was right