Need help! Please help!

[wesgn]

I've gone through 3 motherboards and all of them are having the same problem. I'm currently running and Abit Fatality board with an AMD 64 3700+ SD. When I turn the computer on it runs for about 2 seconds and then shuts off by itself. Once in awhile it will turn on and stay on but I don't get any display whatsoever. It did however turn on one time and I was able to get into the bios. And it ran a ram check as well. I've tried 2 different graphics cards, in all 3 motherboards. Every single setup is having the same problem. Not sure what the problem is at this point. Am I possibly shorting the board out somehow? I also tried a different powersupply. 535watts enermax.

The Graphics Cards I tested: evga 7800gt and a 6600gt BFG.
The motherboard I first tried was an AsRock Dual, which has the PCI-E and an AGP slot. However, when I tried the other BFG it did the same thing.
I've tried this on 2 ASrock boards, both were the same boards. And now the Abit board is doing the same thing. So, I know it can't be the motherboard(s). This is something I've never experienced before. Please help!

 

[Emerald]

Have you tried testing the boards outside the case?
Place them on a phone book incert a video, and memory card. Hook up the power supply and shorten the power button contacts on the mobo to start the system.
If it works this way you know you are shortening out the board inside the case somewhere.

 

[wesgn]

Shorten the power button contacts? What do you mean by that?

 

[Emerald]

use a screwdriver to make contact between the two pins where the power button usually would connect to, to turn on the system.

 

[wesgn]

Ok, Just tried that.
and I have it completely out of the case, sitting on a phone book.
it powered up and shut off in about a second. Just long enough to make the fans spin. I am starting to think it's the CPU (Brand new AMD 64 3700+ San Diego core)

 

[Rugger]

Do you have all of the proper power installed. There is the 24Pin and a 4pin that must be plugged into the mobo. Are you sure that the HSF is properly seated onto the CPU? Did you take off the protective film on the thermal paste on the HSF?

 

[SilverDragon]

A couple of things that may help you troubleshoot your issue further. You didn't mention anything about memory, did you use the same RAM each time you tested? Does the mobo give any type of audible alarm when you first turn the system on? DDR Memory can be very fickle about being seated properly when placed into a motherboard. I've had situations where I needed to clean the contacts on the memory with a clean toothbrush to get a system to boot before. So it may be worth giving that a try.

 

[bourgeoisdude]

"When I turn the computer on it runs for about 2 seconds and then shuts off by itself. Once in awhile it will turn on and stay on but I don't get any display whatsoever."

This screams "processor problem" to me. I know that isn't what you want to hear, but that is most likely the problem. Of course the only way to know is by swapping with a known good cpu to see if it works...or try this cpu in a PC that is already working with another compatable cpu. Do you overclock? When did the processor last work? Did you change any BIOS settings just prior to the failure on the original mobo? Could that have killed the cpu?

Also disconnect your video card completely. If it still shuts off sometimes when you power it up, it is not the vid card. System should stay on even with a bad vid card and should give you a sequence of beeps. Turning on then off in 2 seconds is ALMOST ALWAYS a cpu problem. Sorry man.

EDIT: "I am starting to think it's the CPU (Brand new AMD 64 3700+ San Diego core)"

Oops, didn't read that Yep, sounds like a DOA CPU to me. Hopefully on that first POST (when you got to the bios) you didn't fiddle with the cpu OC settings...if so don't mention it to the store you bought it from!

 

[Rugger]

DOA CPU is extremely unlikely. It's a lot more likely to be user error on install.

 

[cheetahpro]

it sounds like it could be the CPU heat sink and fan on backwards...

 

[bourgeoisdude]

DOA CPU is extremely unlikely. It's a lot more likely to be user error on install.

I've seen DOA CPU's occurr much more often in the past couple of months for some reason. Unlikely, yes, but the symptoms point to cpu failure.

 

[Rugger]

More likely improper contact between CPU/HSF, something shorting the mobo (unused mobo mounting stanchion) or 4pin power not connected.

 

[bourgeoisdude]

More likely improper contact between CPU/HSF, something shorting the mobo (unused mobo mounting stanchion) or 4pin power not connected.

Possibly...but on my mobo even if cpu is missing or P4 connector is unplugged the system will stay powered (and give me some cpu beep codes). However I had a DOA AMD X2 4400+ CPU that caused it to turn off after almost exactly 2 seconds. Traded with another 4400+ X2 and it works fine. I could be wrong but this is something I have had many bad experiences with--DOA CPU's.