Dilema: Computer dead. Suggestions appreciated. Story follows:

[Renegadelost]

First off let me give you a quick thanks for dropping by to read my post. I'm running out of ideas and before I have to buy new parts, perhaps bouncing some ideas off you guys might lead to my wallet not feeling so light.

Description: ( Forgive my long winded story but perhaps the minor details may help. )
I came home and decided I would like to play WoW again. I began downloading patches to update to the latest version before I would reactivate my account. Once finished I remember it saying "The rest of the patch will be downloaded after restarting WoW". I exited the program and restarted it. Same thing. I thought maybe I had to restart the computer so I did. ( Through windows start menu ) Still nothing. I disregarded it and turned off my computer completely because I was hungry. About 25 minutes later:

I return to my computer and press the power button. No response. A long sigh and a screwdriver later I had the side panel off. Checking all power cables connected. All drives connected. I unplugged them all, put them back in. Giving each a good wiggle to make sure they were seated. Fingers crossed I hit the power button again. Still nothing.

Back inside the computer: So the computer will not even start, No power going into it. No fans turn, no beeps, nada. I began to troubleshoot. I unplugged all drives and left only the CPU, and graphics card plugged in. Still nothing.

*Note: I did notice where the USB cable connects from my Internet a light was flashing as if recieving information. Would a light be able to continue to flash if the motherboard was burnt out?

Perhaps its the PSU? I pulled it out and plugged it into an older PC I have. It only requires a 20 pin connector. ( Also no 4 pin extra connecter for the CPU. ) This computer started up fine. The PSU turned on and the computer booted up. I assume the Power unit is fine then.

Perhaps the Power button itself? Worth a try. I disconnected the one from my problem pc and attached it to the test pc. With the same PSU the test pc turned on with the problem pc's power button. Button seems to be working fine. I tried to reverse the power buttons, but the test PC's button did not turn on the problem PC.

CPU? I unplugged and unscrewed the processor, I see no burn marks on the CPU everything seems fine.

RAM? 2 pieces 512mb per: Pulled them out one at a time, switched DIMMS. Nada

BIOS? Dunno, pressed the reset button on the mobo. Removed the battery and reset it. Nada

I've used an older 250w PSU on my troubled PC and it sends power through the board. Its only a 20 pin connection with no extra 4 pin for the CPU ( Fans and such turn on. ) I also put in an older ( Working ) PCI vid card but there is no post, nor does my display screen turn on with the troubled pc.

I'm stumped as to why the 250w PSU would send power through the troubled PC, but the original 480w PSU will not. But the 480w PSU will send power to my older test PC. Any theories?


Well this is where I am friends. Any suggestions, or stories on how you resolved a similar problem would be greatly appreciated. I really don't feel like shelling out any money on parts and then find out that I bought the wrong item.


AMD Athlon 64 3700+ San Diego
MSI K8N Neo4 SLI Platinum
OCZ 2x 512mb
XFX Geforce 7800 GT
Seagate Barracuda 80gb sata
Antec Neopower 480w
Creative SB Audigy 2 ZS
Antec P-160W Aluminum Case

 

[justin3]

It sounds possible that your 4 pin +12 volt rail may be dead on the 480watt.
The 250watt power supply you tried may not be strong enough to power your system. I believe the 3700+ athlon 64 requires a 24pin power and 4 pin 12 volt cpu connector. Try buying a new PSU, and if not try a new motherboard.

 

[oscaryu1]

Sounds like an dying motherboard to me.

 

[Renegadelost]

Response

Well I'm trying to narrow down which of the two is causing the problem. The thought had crossed my mind about the 4pin 12v that connects for the the CPU. But even if I just plugged in the standard 20pin connection from the 480w PSU the board should at least have power run through it to turn on the fans no?

Also, I think the 250w PSU would be enough for the motherboard, PCI graphics card and the CPU to at least POST or give some sort of beep indicating its some how responding?

Thought: Do I need a sound card installed to hear the POST beeps? My motherboard requires a -5v to use the on board sound. Which neither of my PSU's have. I use PCI sound cards for sound, should that be put in when trying to get a response with my 250w PSU?

 

[oscaryu1]

Either your motherboard has an onboard POST speaker, an speaker conencted from yuor mobo to the case (case speaker), or you dont have one at all (like my IP-95)