PC boots on for ten seconds then shuts off

[yayman]

Hey everyone I've been having this problem ever since I built my custom PC. The time it shuts off is pretty random, sometimes it could be running for 5hrs then it shuts off or it could be running for five seconds then it shuts off. However, recently the lifespan is pretty short (about 30 secs). I've notice that when I leave it alone for awhile it has a better chance of lasting longer. This leads me to suspect that it could be overheating. I don't think it's a PSU problem because I replaced my 500w with a 700w. Its also not a CPU issue because I've replaced that as well. Now back to the overheating question, I've taken readings of my CPU temp and it is at a stable temp (24C). Could it be the RAM cards heating up? If so how can I measure their temp? I only have one case fan. Also I've heard something about the power button sticking, that doesn't seem to be the problem but if so how would I fix it?
System Specs:
XFX nforce 750sli mobo
EVGA 1G 9800 nvidia gt video card
700w PSU
Intel Core 2 Duo E8400 Wolfdale 3.0GHz LGA 775 65W Dual-Core Processor
Seagate 500gb SATA HD
Windows 7

[liljim]

what kind of 700 watt psu is it?

24c seems inaccurate to me, what are you using to get this reading?

[yayman]

OCZ 700w, I am using both speedfan and my mobo's bios to monitor temp here's a list of the bios' readings
CPU Temp 22 C
System Temp 24 C
CPU Fan speed 1722 RPM
Sys Fan 1 speed 1257 RPM
Sys Fan 2 speed 0 RPM (kinda of confused on this one)
CPU Vcore 1.08 V
3.3V 3.344 V
5V 5.045 V
12V 12.408 V

[liljim]

Wow, thats great temps then. Being only 65 watts must help alot. CPU is obviously ok so that essentially leaves 2 things, bad mobo or bad, overheating psu. Ram would power you off, (normally) if anything it would BSOD or freeze but no power loss. Video is much the same. PSU could be overheating due to a slow/non working fan or simply weak from a failing/leaking capacitor. I lean towards saying the psu needs to be rma'd. The only thing that throws me a little is you say you had this problem with the previous psu as well. Was the problem exactly the same with the 500 watt?

[yayman]

Not exactly, with the old PSU the computer would stay on but the monitor, keyboard, and mouse would suddenly not work, also when it did this I heard the fan inside whirl up like crazy. I just ran System Mechanic (not sure if it's a good program or not) and it basically told me that my system's health is crap. Some problems that it stated were Registry Problems and Hard Drive issues. I am just so confused by all this seeing as the computer has not even been used for more then a couple weeks.

[liljim]

system mechanic has to say somethings wrong just so you dont feel like you wasted your money : )

[yayman]

lol that makes more sense. I was looking at my powersupply and i noticed some random white crap sticking on the copper coils. I'll try to post some pics to show.

[yayman]

Ya so I took apart my PSU and there is definitely something wrong with it. There's all this white goey looking stuff in between capacitors and coils. The PSU I have has been reconditioned but I doubt the white stuff was a byproduct of the refurbishing.

[liljim]

sounds like bad caps, id say there leaking.

[yayman]

Its funny tho, the goey not actually coming out of the caps its more like sticking to them from the sides...I probably just gonna get another PSU that hasn't been refurbished..