Power issues w/ new build

[jariley]

I'm a semi-noob and I recently built a computer with the following components:

Gigabyte GA-965P-DS3
Intel Core 2 Duo E6600 Conroe 2.4GHz
Corsair XMS2 2GB SDRAM DDR2 800 (PC2 6400)
Western Digital Raptor WD1500ADFD 150GB
Seagate Barracuda 7200.10 ST3320620AS 320gb
XFX PVT71GUQL3 Geforce 7900GT 256MB
Creative Sound Blaster X-Fi
Sony DVD
Nec DVD-R
floppy
Antec p180b
Antec Smartpower 2.0 SP-500

After assembling the components I boot for the first time and after about 30 seconds the computer suddenly turned off. I turned it on again, checked that all the fans were running and confirmed they were. A few moments later it switched off again. I double checked all the connections, etc. and then turned it on again. It turned off more quickly, probably something like 15 seconds. I consulted manuals, triple checked connections again, and about 10 minutes later turned the computer on again. It lasted the original 30 seconds or so and then switched off abruptly again. I have a backlit keyboard and noticed that a few seconds before the computer switched off that the backlight switched off.

The way it gradually takes less and less time to shut down led me to believe that it could be a heat issue, but with the case open and all the fans running, including the heatsink and power supply I can't see how that could be the problem. The boot goes completely normal other than suddenly powering off - the system recognizes the compenents during startup and can get into bios or windows setup for a few seconds. This led me away from the motherboard because it doesn't seem that the system would boot normally and then just shut off with no error messages. I checked the caps and looked over the board anyways and it seems ok based on a visual guide I found in the forums here.

I figured it had to be the power supply, and had it replaced. I just tried the new one and have the same problem. I supposed it could still be the motherboard, but I thought I'd see what you guys think prior to taking the whole thing apart. Is it possible that it could be the case's soft switch? Let me know if you have any ideas. Thanks for your help.

 

[The Boston Dangler]

Sounds like the CPU cooler isn't proerly installed. BTW, you can put all the parts together and test before putting it in a box.

 

[xboxist]

Is there a chance at your CPU cooler isn't properly and securely fastened? Your board might be auto-shutting off due to CPU heat.

Do you have a test computer handy? I'd test the RAM next too.

 

[SparkyJJO]

The system should at least keep running if the RAM is bad. Heck I've turned a mobo on with no vid card, RAM, or CPU But it does sound like the heatsink is making poor contact (wonder if the infamous C2D concave IHS is to blame here). If you have 30 seconds see if you can get into the BIOS and to the hardware monitor screen and check the CPU temps if possible.

The switch is a possibility as well, I had a system that had a bad switch. One way to test it is to disconnect the power switch from the mobo, then plug in the reset switch there instead and see what happens - remember to hit the reset not power switch to turn it on

 

[jariley]

I took off the heatsink and cleaned some of the excess artic silver and put the heatsink on with a some more oomph. It seems to work fine now which makes me feel really, really stupid. If the problem comes up again I'll let you know. Thanks for all your help and your prompt replies.