Why can't I get this thing to turn on??!?!

[DougEFresh]

Ok so I have a Dell Dimension 8400 I'm trying to fix for a friend. I cleaned the dust out of but when I went to power it on it didn't do anything. I tried different cables and power sources. The light is green on the motherboard but nothing else. I shorted the psu and the psu fan turned on and seemed ok. I removed the ram, video card, and everything else one at a time trying to see if one of them was bad and still nothing. Is there a way to bypass the front power switch to turn the computer on? If that isn't the problem it has to be either the cpu, motherboard, or power supply (I'm thinking mobo). I found a motherboard on ebay for $60. I can't think of anything else to do other than order parts and replace them. Anyone know where I can find parts for this computer for cheap? I saw a used dimension that had everything but the cd drive
and hard drive on craigslist for $50 but it already sold. Any insights or help would be appreciated. Thanks.

 

[r_manic]

I also think that your mobo got fried.. Concentrate first on finding a replacement mobo. eBay is your friend in these cases.

 

[DougEFresh]

Update:

I installed the new motherboard along with a new I/O panel board. Tested the power supply with a voltage meter and it read 5 and 12. I also shorted the p1 connector and put a case fan on it and it worked fine. So looks like it's not the motherboard or the power supply. I ordered a new cpu for $24 and if it doesn't work I don't know what the hell is wrong with this thing. Any other troubleshooting steps to try would be appreciated.

Thanks

 

[DougEFresh]

What about the about the the button on the front of the case that you use to turn it on and off? Any chance it could be broken or lose? If so, how do I get the front panel off to look at it?

 

[DougEFresh]

So I ordered a new front panel switch see:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=360134061204&ssPageName=STRK:MEWNX:IT

and a new cable that goes from the I/O panel to the motherboard:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=360208020638&ssPageName=STRK:MEWNX:IT

I would have a new motherboard, I/O panel and new cable to go to the motherboard, a new front ON switch panel and cable, and a new CPU. If I can't get this thing to turn on after all of this I have no clue what to do.