Can't Start PC- Powers off immediately- Short Somewhere?

[Sands]

Hi Guys

Hi Guys

New Build.

New CORSAIR CMPSU-650HX 650W PSU and when I hit the start button it starts and turns off within the span of a second.

Is this a short?

Shall I try a rebuild?

Any tips greatly appreciated.

--------------------------------

ASUS P5E3 PRO LGA 775 Intel X48 ATX Intel Motherboard
Duo Core E8500
CORSAIR CMPSU-650HX 650W ATX12V v2.2
OSC Platinum 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600
EVGA 896-P3-1171-AR GeForce GTX 275 Superclocked Edition 896MB
LITE-ON DVD Writer - Bulk - Black SATA Model iHAS224-06
Western Digital Caviar Black WD1001FALS 1TB 7200 RPM SATA
APEVIA X-SNIPER G-Type X-SNIPERG-BK Black SECC Steel ATX Mid Tower Computer Case

 

[jsc]

It could literally be anything.

Our standard checklist and troubleshooting thread:
http://www.tomshardware.com/forum/261145-31-read-posting-boot-problems

Work through the thread. Try the breadboarding section to eliminate problems with your case and the possibility of a short somewhere.

 

[Hellboy]

It could literally be anything.

Our standard checklist and troubleshooting thread:
http://www.tomshardware.com/forum/261145-31-read-posting-boot-problems

Work through the thread. Try the breadboarding section to eliminate problems with your case and the possibility of a short somewhere.

remove the board from the case and make sure the 4 pins on the heatsink are correctly placed in their holes..

the white pins must go through the holes and click in place on each corner..


this is common with socket 775 if your not used to them

 

[hefox]

My suggestion is to assemble the components on a table and see if you have the same problem.

 

[Paperdoc]

One little thing to check for: on most motherboards the BIOS watches the CPU fan and monitors its speed through the CPU fan connection to its mobo pinout. On many that monitoring process includes an immediate shut-down if the BIOS detects no CPU fan running. For cases in which you do not have the fan connected normally and thus have no CPU fan speed signal, you have the option in BIOS Setup to disable that feature.

What got me thinking, though, is the time frame you specify. A problem of inadequate cooling (for example, because the heatsink mounting is wrong) normally will not cause a really fast shut-down - it only happens after the CPU heats up too fast, and that takes many seconds. An instant shut-down most commonly is a something like a short circuit. To check that follow what others already have said - remove from case, do the breadboarding process, and then follow the other troubleshooting procedures.

By the way, if the breadboarding experiment demonstrates that it all works outside the case, a common source of short circuits in a new build is misplacement of standoffs. Those are the short brass pieces about ¼" long that screw into threaded holes in your case and, in, turn, have threaded holes in their tops for screws that fasten the mobo to them. They must be placed in your case originally so that there is one under most of the mounting holes in your mobo. But most importantly, there can NOT be any mounted under the mobo where there is NO mobo hole - that will usually cause a short. While you're in the case removing things, watch also for loose lost screws that got under the mobo.

 

[Sands]

Thank you: jsc, helloboy,hefox and Paperdoc .

Gives somethings to go on.

I appreciate the tips!

I shall try the run the mobo outside the case deal.

Thank you!

 

[Sands]

Solved!

I had one case stand off to the Mobo that didn't have a corresponding hole in the mobo!

Noobie move.

I didn't keep count of stand off and screws!

All is well now!

Thanks all!

 

[jsc]

A surprising common mistake.