Help! Computer won't turn on =(

[Srezic]

Hi everyone,

I woke up this morning and my computer was off. I pressed the power button and it wont' turn on (hooray for my luck the day Oblivion comes out).

So I pop her open and the motherboard light is still on (which I assumes means the mobo is getting power still). I unplug and replug in all the connections to make sure it wasn't a loose cable(not sure how this would happen). I try the power button again, and one of my case fans twitches for a second, which makes me think now that the power supply is dead (or the power button in the case).

Here's a list of some of the things in my computer (which I built):

nVidia GeForce 7800 GTX 512 (power hungry bastard)
Asus A8N-SLI Premium
AMD Athlon 64 4000+
74GB WD Raptor maindrive
250, 80GB EIDE slave drives
Enermax EG651-P VE (24P) 550W (I think the culprit).
Corsair XMS twinx1024c2pt


So, a friend had me try turning off the power supply all together, and turning it on a few minutes later. This time my CPU fan and case fan both twitch for a little bit. I'm thinking the power supply somehow got overdrawn by my graphics card (I didn't plan on getting that card when I had my PS in mind heh).


Anyway, if there's anything I left out which would help determine the problem, please let me know. THANKS! =)

~Srezic

 

[wpshooter]

Did you reseat your video card ?

 

[Srezic]

Yes, I reseat everything except for the CPU (trying to avoid that if i can).

Here's a post about the deluxe version of my motherboard, which doesn't make me feel to great about my predicament =/:

http://hardware.mcse.ms/archive69-2005-10-247694.html


Of course the guy never came back and said if it fixed it or not, but I assume it did since he didn't post again.


I'm about to test my PS with the paper clip test, just to see if it will run by itself, but I have no paper clip, so gotta run out and get one.

~Srezic

 

[wpshooter]

Before you do that, have you tried resetting the CMOS via the motherboard jumper - make sure you follow motherboard manual instructions EXACTLY to the letter ?

 

[JDMnAR1]

Based on what you have said, my money would be on the PSU. With presumably no changes to your system occuring overnight, the likelihood of it being a loose connection or poorly seated component is basically nil. The fact that you get a momentary spin on your fan when trying to turn it on would lead me to believe a PSU failure of some sort - either component failure or thermal failure. Of course, resetting your CMOS won't cost you anything, so might as well give that a shot before purchasing another PSU.

 

[Srezic]

thanks for the input guys. I'll try to reset the CMOS soon.

I am also going to try the paper clip PSU test to see if it even turns on, because right now it doesn't. But CVS didn't have metal paper clips, only vinyl-covered ones, so BAH.


Anyway, once I find out more i'll get back to the thread. I really do appreciate the responses.

~Srezic

 

[Srezic]

Ok, so I localized the problem.

I have the 2 following parts:

Enermax EG651-P VE (24P) 550W Power Supply
ASUS A8N-SLI Premium Motherboard

On the motherboard there is a power plug with 4 pins labeled "ATX12V". There is a special 4-pin cable which comes with the 550W which goes directly into this.

If I unplug this 4-pin cable, everything 'starts up', but Nothing shows up on the screen. I assume it needs this to make the motherboard work correctly (for whatever reason).

If I plug in the 4 pin connector, I get the results I got before with nothing starting up.


What I need to know now is
1, What is this ATX12V connector used for
2, is there any way to bypass this
3, is there a way to test if the power cable for the 4-pin connector is broken or if it's the motherboard receiving side screwing things up?


Thanks again

~Srezic