Help with troubleshooting my PC! I'm desperate :(

[matmike2]

Hey!
I have tried to build a new PC with the following components
1. AMD AM2 X2 3800+
2. MSI K9N SLI Platinum
3. 2Gb (2X1Gb) Corsair TwinX XMS2, DDR2 PC6400 CAS4
4. Gainward Golden Sample Bliss 512mb 7900GT
5. Antec Neo He 550W PSU

I'm having the following problem. Whenever i switch on the PC, it powers-up for 2 seconds and then switches off at the exact same time. I have managed to boot up the PC twice and have installed Windows XP and Oblivion (graphics are amazing btw!). However, when i tried to boot up next time, i had the same problem, and the computer switched off 2 secs later. I have taken the PC to 2 so called "computer experts" and they cant seem to agree on the likely cause.
I have a few suspicions:
1. A Faulty PSU
2. A faulty Motherboard
3. Faulty RAM
One of the computer guys managed to run the system by changing both the RAM and the PSU. However, i didnt believe him when they said they were both faulty as i think he was trying to cheat me to try and make me buy some new ram from him! What are your suggestions? I', really desperate! I've been trying to resolve this issue for 3 wks now! Thanks for the help!

 

[matmike2]

Thanks for the help! I'm getting my computer back from the workshop tomorrow. I will see if i can manage what you suggested! Already downloaded memtest but couldn't get the system to stay on for long enough for me to test it!
I just have 2 questions:
1. If it were a motherboard issue, would the system boot up at all? I did manage to get it to boot up twice!
2 Also, if it were a PSU issue, would the PC have booted up fully? The system has booted up fully twice. Would a faulty PSU allow me to do this?

 

[crazyhandpuppet]

While the RAM may be faulty, it wouldn't be my first suspect. Most likely I'd fault the Power Supply first. Shops should have a PS Tester that they can hook up, test, and confirm in under a minute. I always test the PS before I put it into a computer. I have just seen way too many broken fresh from the box from various brands. If the people you took it too cant hook it up and diagnose the PS that quickly, I'd be suspect as to whether they are "experts". An issue I've had in the past, though primarily with Biostar AGP boards, is that the Video Card needs some extra love and a good hard shove when it is installed or I'd get various problems, including yours. Could just be something shorting out from touching, but my bet is on the PS first, not the RAM.

 

[matmike2]

Thanks for the help guys!
I've had some success!
I took the PSU to the person that sold it to me. They plugged it into a PSU tester and voila! A FAULT! Woohoo! They're gonna give me a replacement on Monday. You dont think there could be a fault with anything else do you? Another PC guy i took it to said it was both the RAM and PSU that were faulty. I highly doubt him though. I thought Corsair tested their RAM just before they packed it. I think the guy was trying to cheat me and make me buy a new set of RAM.

 

[badge]

Thanks for the help guys!
I've had some success!
I took the PSU to the person that sold it to me. They plugged it into a PSU tester and voila! A FAULT! Woohoo! They're gonna give me a replacement on Monday. You dont think there could be a fault with anything else do you? Another PC guy i took it to said it was both the RAM and PSU that were faulty. I highly doubt him though. I thought Corsair tested their RAM just before they packed it. I think the guy was trying to cheat me and make me buy a new set of RAM.

Hope the new PSU solves the problem. I have had a perfectly dependable computer suddenly refuse to load software, hang, give error messages, etc. Pulled out two Corsair XMS 256 meg dimms and left the other two dimms in and had it load up the software and run flawlessly. So, I have RMA'd Corsair XMS before. The RAM apparently jusr failed after a couple of years use. If the power supply doesn't fix it it may be your RAM failing. Your description in your original post sounded like you were describing a short to the system. Anyway, glad you got a bead on getting it going.