System Shuts Off After 15-30 Seconds

[sularus92]

This is my first time posting here and I wish it were under better circumstances. I have put together a new system, here are the specs:

CPU: AMD Phenom X4 9850 2.5 GHz
MoBo: ASUS M3N78 PRO AM2+
PSU: COOLER MASTER REAL POWER PRO 550W
CPU COOLER: COOLER MASTER HYPER 212
RAM: CORSAIR DOMINATOR 4GB 2x2GB 1066
HDD: SEAGATE BARRACUDA 750 GB SATA 3.0
DVD: SAMSUNG WriteMaster SH-S203N

My issue (which is driving me nuts!) is that after turning the system on after 15-30 seconds the system completely shuts off. No blinking LED's just shuts completely off. I can make it to the main bios screen and that is it. I have read a couple of things online and tried putting together the basic components of the comp out side the case (RAM, CPU, and CPU COOLER) thinking perhaps I was grounding out the MoBo, it still does the same thing. My power supply has a red LED on the back that is supposed to light up if it is bad but it has never come on. Not sure what else to try. I am sure it is either the MoBo or the Power Supply. Any ideas on how I can be sure which one it is? And no I do not have access to another ATX system to try out the power supply. Please help it would be much appreciated. Thanks.

 

[yonef]

1) Does you system shuts off while you are in BIOS?
2) What Graphic card do you have?
3) Did you plug ALL power connectors to the graphic card?

On first thoughts, this sounds like a PSU problem (defective one), not sure

 

[sularus92]

Yes, it shuts off while I am at the main bios screen.
There is no graphic card at the moment, it has a decent on-board graphics.

 

[steffato]

Please try resitting your CPU cooler. It is probably not installed firmly on your CPU and the PC shuts itself down because of overheating.

 

[rdb]

When you set the CPU and cooler, what paste did you use. Is the cooler connection tight.

 

[dhvd79a]

Yes, it shuts off while I am at the main bios screen.
There is no graphic card at the moment, it has a decent on-board graphics.

I've seen a couple of things do this. Bad Power supply, bad power supply cable, memory not set properly, over heating due to no HS or improperly installed HS.

 

[sularus92]

I used the thermal grease that came with the cooler, I will try and re-apply the grease and see how tight the cooler is.

 

[sularus92]

applied more thermal grease, tightened the heat-sync and still does the same thing. Not sure what to do anymore this is driving me crazy.

 

[yonef]

You have to find any other PSU to try with. Most probably defective PSU or power cable as dhvd79a said.
You can also try to look at "hardware monitor" page and see any suspitious temperatures there.

 

[nussrods]

Not to be insulting, but did you plug in both the 24 pin power connector, and the 4 pin cpu power connector to the motherboard? You may need to manually set the voltage and timing for the ram in the bios, if it will let you. Try powering it up with only one stick of ram installed, if this doesn't work, try the other stick of ram.

 

[azone]

I once had the same problem with an intel p4 2.4 with bent pins. I straightened them all out over and over and they were perfect every time I checked, but it kept shutting off, never could resolve it. I think a small capacitor or resistor could of popped from the static when I was working on it on either CPU or MOBO. MUST be careful and static free when working on this crap.

 

[sularus92]

A bit late for this but I want to thank all of you who replied but especially for the advice to tighten down the CPU fan. Thanks guys this forum is great.