Computer turns on then off.

[tinbanger]

Ok, here's the deal. I built my computer 1.5 years ago. Ever since then when I power it on, it turns on for 5 sec or so starts to boot, then turns off for about the same amount of time, then turns back on, and runs fine. Please help.
My build;
EVGA P55 SLI 132-LF-E655-KR LGA1156 Intel P55 ATX Intel Motherboard

EVGA 01G-P3-1158-TR GeForce GTS 250 1GB 256-bit DDR3 PCI Express 2.0 x16 HDCP Ready SLI Support Video Card

Rosewill Green Series RG700-S12 700W Continuous @40°C,80 PLUS Certified,Single 12V Rail, Power Supply

Intel Core i7-860 Lynnfield 2.8GHz LGA 1156 95W Quad-Core Processor BX80605I7860

OCZ Gold 6GB (3 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Low Voltage Desktop Memory

Thanks,
Tin

 

[tsnor]

Can you manually set your memory speed and voltage? There was a very similar thread where bad memory voltage auto set by the bios, followed by an automatic restart with conservative settings was the root cause....

Also read this and see if you see something. http://www.tomshardware.com/forum/261145-31-perform-steps-posting-boot-video-problems

 

[tinbanger]

Can you manually set your memory speed and voltage? There was a very similar thread where bad memory voltage auto set by the bios, followed by an automatic restart with conservative settings was the root cause....

Also read this and see if you see something. http://www.tomshardware.com/forum/261145-31-perform-steps-posting-boot-video-problems

Thanks for the reply i checked my bios and the dimm voltage was 1.5 when my mem is 1.65 so i changed it and it still does the same thing.
When i bought my motherboard it was double channel and I on accident bought 6gb triple channel mem would this cause my problem.

Thanks,
tin

 

[Proximon]

Try running with just two sticks, in the correct slots.

Use CPU-Z to check your memory stick settings. Look under the SPD tab to discover some conservative settings available with the RAM, then make those MANUAL adjustments in the BIOS.

If that doesn't work, reset the BIOS to default using the method described in your manual.

Then update the board with the latest BIOS, being careful to follow instructions precisely.

Try the first two steps again at that point if needed.

Finally, this can also happen if you are losing power to the board every time you shut down. It might not be apparent. It could be bad +5VSB power from your PSU.... Standby Mode power that is always supposed to be there.

So if you are turning off the PSU from the back, unplugging it, or turning off the power at the power strip, this would be normal and expected.

 

[tinbanger]

Thank-you Proximon,
I flashed the bios with the latest version, and to my surprise it worked. it turns right on, no more on, off, on,

Thanks,
Tin

 

[tinbanger]

Best answer selected by tinbanger.