computer hard shutdowns for some unknown reason

[importedalien]

 I'm having problems with my comp. It's my first build so I have no clue why it's shutting down on me. I don't believe it is a over heating problem. I've replaced my motherboard and RAM thing that was the problem, but the problem still ensues. I will turn on my pc and it will work for 15 min or less and then shutdown. I was thinking of replaces the CPU, but I'm concerned that it will not solve the problem. If anyone has any advice it would be much appreciated.

My specs are:
CPU i7-950
Mobo EVGA X58 classified 3
RAM G-Skill Ripjaws 12 gb
Graphics card evga gtx 460
Power supply Antec 850 watt
Hardrive seagate barracuda 7200.12 500gb

I'm still kind of new at this. I know very little when it comes to pc's.

[hartbeatmr]

Good morning importedalien

Nice set up you have here but lets see if we can better help you.

Now I am not being a wise guy but you did connect the extra power plug into the motherboard not just the 24pin atx connector.

That will cause the system not to work.

Did you try to boot the system with say 1 stick of ram?

During boot and in windows is running is the CPU fan running - Is the fan a Intel box set fan (ie retail cpu set) that has CPU and fan together. If this was a Intel fan did the protective film /cover get removed from the bottom of the heatsink? before placement.

Did the 1 or 2 (8pin) power connectors get plugged into the video card?

Very rarely are Intel CPU's defective, when the PC shuts off does it reboot or just stay off?

Also as a test take the MoBo out of the case set it on a flat surface use the antistatic bad the MoBo came in and put it under the board. Now plug in the video card, CPU and memory and hard drive. Now connect mouse and keyboard and monitor to the board and fire it up does sit stay running if so the MoBo is shorting out on the computer case some how.

Well please let us know how you make out or if you want just send a PM, Mike     

[Allan]

My initial guess is heat or power supply. Let's rule out software - please boot to safe mode - does the same thing happen?

[Salmon Trout]

or if you want just send a PM, Mike   

Do we really want people setting up private help channels?

[Allan]

Okay, new member - doesn't understand how our forum works.

hartbeatmr, we prefer all topics be handled on the forum for all to see and learn from. Most support forums frown on suggesting support via PM. Thanks.

[importedalien]

Heatbeatmr: I've done pretty much everything you asked. I used the one stick of RAM. I was using a CoolMaster heatsink, but I thought that might of been the problem so I switched to the stock Intel version. I've also replace the thermal compound. I plugged in 2 power conectors in the graphics card. When it powers off it stays off, all the led lights on the motherboard stay on though. I haven't tested out on the anti static bad yet, ill try that tomorrow.

 Allan: It shutdown in safe mode, it will also shutdown in BIOS. I could be wrong but I don't think its over heating. I've cleaned it out fairly well ( used air can on heatsink and outer fans ). I have not cleaned the power supply though, does the power supply overheating cause problems for computer? The LED lights on motherboard stays on. So initially I don't believe it the power supply.

I'm using my phone as my only source of internet, so I do apologize for any random word that doesn't fit into sentence. Auto-correct is kind of a pain.

[BC_Programmer]

My computer build also experienced this weird sort of issue where it would power off/reboot intermittently. I was able to determine the CPU power cord to the motherboard was not as snug as it should be- pushed it in, and haven't had issues since.

[importedalien]

Everything seems to be put in right. It's worked for about a year now and now it shutdown.

[Computer_Commando]

I'm having problems with my comp. It's my first build so I have no clue why it's shutting down on me...

This statement seemed to imply it was new.  You now say it's been working for a year?  No other changes recently?
If it shuts down in BIOS, it could be the PSU, CPU cooling fan is stuck. graphics card, or motherboard.

... Allan: It shutdown in safe mode, it will also shutdown in BIOS. I could be wrong but I don't think its over heating. I've cleaned it out fairly well ( used air can on heatsink and outer fans ). I have not cleaned the power supply though, does the power supply overheating cause problems for computer? The LED lights on motherboard stays on. So initially I don't believe it the power supply...

If PSU cooling fan is not operating, it will quickly overheat & shutdown.  Lights on motherboard don't mean a lot, unless you know what the lights indicate.

[BC_Programmer]

This statement seemed to imply it was new. 

well, he/she did say first build and not new build.

[Computer_Commando]

well, he/she did say first build and not new build.

True, but, nevertheless, it indicates something has recently failed.

[importedalien]

Originally it would shutdown when playing games or watching netflix. My friend told me it was overheating. So I cleaned it out, now he's not to certain what it is. Again I have replaced my motherboard and RAM, so two new pieces. The only thing I can think of is either the power supply or the CPU.

[Computer_Commando]

Light a light bulb, CPU's pretty much work or they don't.  There is no middle ground.

[hartbeatmr]

Good evening

      OK I am sorry. I miss-understood you I thought this as a new build / First build. But with this PC in use for year I don't know if it would be shorting out on the case know that I know the age of the PC.

      I do agree with others here even knowing Antec makes a great product the PS can be failing / over heating. With all your components you may not realize how many watts your rig needs

This is just an est of wattage only to start the PC this is not including when things are getting ramped up. 
Your CPU 125+ watts
MoBo will be using some also like maybe 40-100 watts for chip sets etc
Video card will be about 160 watts
Each fan about 5 Watts
Reg PCI card(s) 10 -20 watts each
Hard drive will be about 8 - 15 watts maybe a little more if under heavy load
For Ram I always figured 5 - 10 per stick
CD and or DVD drives will be about 10 - 20 watts for each drive

So it does add up as far as how much your rig will use every time it starts.

But like in some of the post here Intel CPU's normally don't go bad. In about 12 years I have had to replace a hand full of bad Intel CPU's that may sound like a lot but in the number of systems I have built / worked on / deployed that is really a very low % of bad ones.