PC won't start

[pmonett]

I am at my wits' end.

I have an ASUS A8N SLI with 2x1GB of DDR, 2 optical DVD/RW drives on ATA, two 200GB SATA HDDs, an Audigy 2 card and a 8800GSX. To power that, I have a brand-new (just replaced the old one) 650W PSU from Sweex.

Yet, when I push the button, I get all the LEDs lighting up, then nothing.
The fans don't start, the HDDs don't start, the DVDs don't start, nothing.
I am 100% certain everything is correctly wired, but nothing starts.

I used to have a 500W PSU and a 7800GTX when the problems started four/five weeks ago. I thought it was the case, so I changed the case. Nothing.
I then thought it was the PSU, so I bought one four days ago. Just for the kicks, I also bought the 8800.
Lacking time, it took me three days to get everything wired up. I give it a try tonight, and still nothing.

Now I dispair. What can I check ? I'm sure 650W should be enough, where's the issue ?

Please give me another idea.


I've got nothing to hide, and I'd very much like to keep that away from prying eyes.

 

[Johnthephoneguy]

if you have changed the case (which really is only the start button that matters for that) and you have changed the power supply, you are left with 2 possiblities.

1. the CPU is bad. if it was just overheating I would think it would at least post.

2. The motherboard is bad.

you can try starting with a barebones system to ensure there are no other issues but most likely its 1 or 2.

JohnThePhoneGuy

"If I can't fix it, it's not broke!

 

[kmcferrin]

Mistake number one was throwing the 8800 into the mix when you bought the new PSU. Assuming that the old PSU was the problem, and that the new PSU had enough juice to power the old config, you just upped the draw by adding a much more power hungry video card to the mix. So now you can't be sure if you "fixed" the previous problem by getting a new PSU, but then created a new one by getting the 8800. If you are trying to isolate a problem, the best practice is to only change one thing at a time.

That being said, I would strip the system down to mainboard, CPU, memory, and video card and see if you can get anything to happen. You should have more than enough power for just those components. If it works, start adding components one by one until you get the problem again.

 

[pmonett]

I think you're both right. I still have the 7800, so I'll trip it down and give it a try.

I'll keep you posted.

Pascal.


I've got nothing to hide, and I'd very much like to keep that away from prying eyes.

 

[macten88]

I would buy a psu tester and test the old psu. If it's bad, it may have taken out the motherboard...

 

[Aussie2]

Try your ram in slots 2&4 also have a close look
at your NF4 chip look for discolouration

Had probs myself with these boards

Two boards failed to detect ram in channels 1&3
where as they were both previously stable with ram in this configuration for 6 and 10 months

One board failed to post on closer inspection noticed
what first appeared to be dust on the edge of the NF4 chip
but was infact a burnt chip but in all fairness this board
was purchased used from ebay the above two were purchased
new fom a local vender

 

[Bigbc1224]

Check the grounds. For the led's to come up but nothing to run like that there might be a short somewhere. Pull Drives, memory, peripherals etc, and see what you get.

 

[pmonett]

Okay, thanks for the interest everyone. I have determined that the PSU was indeed at fault. Only three weeks old, and poof !

Needless to say, I will bring the unit back and get a full refund.

Thanks to all !

Pascal.


I've got nothing to hide, and I'd very much like to keep that away from prying eyes.

 

[acewarlock]

When all else fails, Put it back the way it was and if it works then. change 1 peice at a time until you hit the problem.

 

[35Pete]

Plugging stuff in might have caused the mobo to shift on the mounts. You may have a short of the mobo to the case. But first things first.

Unplug all peripherals. Now, with only the DDR and the CPU power up the mobo. If the fan spins then a card or peripheral is bad. If not then...

Unmount your mobo and place a small piece of electrical tape between each chassis mount and the board. Make sure that they are electrically isolated from each other. Then retest with DDR and CPU. If the fan powers up then add one card/peripheral at a time (with power off!) until all is well.