# cpu overheating on startup



## typsu32 (Aug 2, 2009)

I just built a new PC, and when I went to boot it up for the first time, it would start, and then turn off for a while. Eventually we got it to get to the bios, and when i checked cpu temps i got a temperature reading of 95 c. I'm not sure how this would be possible on start up. Can anyone help me figure out the problem? i was thinking that it would either be the cpu, bios, or mb was resposible. 

Thx in advance.


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## manic (Aug 2, 2005)

Is the fan on the cpu running? Did you use thermal compound on the
cpu/heatsink? Did you apply it properly?


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## typsu32 (Aug 2, 2009)

all fans are running, the thermal compound was pre applied to the fan's heatsink. everything seems to be running correct. any ideas?


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## makinu1der2 (Jan 1, 2008)

Hello typsu32,

Post the specs of the system.


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## Tumbleweed36 (May 14, 2005)

Are you certain all the legs are down tight and snapped clear in on the CPU. Those must be solid to the motherboard.


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## typsu32 (Aug 2, 2009)

system specs:
intel q9550 
gigabyte ga-ep45 ud3p mobo
700 watt psu
4gb ddr2 ram
bfg gtx275 gpu

The legs were tight down. Even took it off and restationed it to see if that would help. I'm completely confused as how on start up it could be 74C-75C. within 30 seconds it climbs to 94C. The system temp seems normal at around 34C. Thanks for your help guys.


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## speedster123 (Oct 18, 2006)

Did you use artic 5?
http://www.arcticsilver.com/instructions.htm

What make and model power supply is installed?


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## typsu32 (Aug 2, 2009)

No, i used the thermal pad on the heatsink that was applied by intel.

The psu is an OZC700SXS.


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## speedster123 (Oct 18, 2006)

artic 5 is the way to go, the pad might be compromised.


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## Tumbleweed36 (May 14, 2005)

Agree with Speedster, redo the thermal paste:

Applying Artic Silver Thermal Paste


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## typsu32 (Aug 2, 2009)

I can understand how the thermal pad might have something to do with it, but even if i were to run the CPU without a cooler, I can't imagine how it would be that hot as soon as i start up the computer. 

should I do an RMA for the CPU or mobo? Is there a chance I ruined one or the other?


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## speedster123 (Oct 18, 2006)

possibly
but definately use the artic 5


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## grimx133 (Jan 15, 2008)

A cpu can overheat in seconds. In some cases it can cause a machine not to display anything, it shuts down before anything has time to come up on the screen. Usually when it heats that fast there are serious air gaps due to the heatsink not being solidly mounted, as Tumbleweed36 mentioned in post#5. Redo the paste with some properly applied Arctic Silver 5 and make doubly sure that the heatsink is mounted "rock solid" and then see where you are. Properly applied means very little, I spread the paste into as thin a layer as I possibly can, while ensuring that the top of the cpu is completely covered. Spreading isn't required, as per the AS5 instructions, but I prefer to do so.


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## typsu32 (Aug 2, 2009)

Ok, makes sense now. What would be the chances that the cpu is fried? Or is there a chance that anything else has been ruined. 

Thanks for all the help guys


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## Tumbleweed36 (May 14, 2005)

I don't think anything is fried...change that paste and then we can talk about results.


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## typsu32 (Aug 2, 2009)

first of all, i just wanted to say thanks to everyone for their help. I have the temps down to 46/47C and they seem to stay there. 

i know that is a high temp, so could anyone tell me what i could do to lower the temps? all fans running, and i believe i put the thermal paste on correctly


thx


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## Tumbleweed36 (May 14, 2005)

Tell us about your fans....what fans, where located, which direction are they blowing?


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## grimx133 (Jan 15, 2008)

It's an acceptable temp, though if the cpu is stressed and running at 100% it would probably go into the low to mid 60's. Low 60's is about as high as you'd like it to get. You should be fine as it is, but if you want lower temps you either need to try a different heatsink, or see about increasing the airflow in your case.


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## typsu32 (Aug 2, 2009)

the fans are one 120mm intake in the front bottom and a 120mm exhaust in the rear. 

i have two 80mm fans, but as this is my first build, i don't know exactly how i should mount them. 

any recommendations on a decent heat sink? the comp is going to be used for cad and racing sims like iracing and lfs.


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## Tumbleweed36 (May 14, 2005)

Do you have any fan holes on top of the case or on the side of the case?


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## Phædrus241 (Mar 28, 2009)

If possible you should mount the 80mm fans as a side intake and a top out take, if you don't have fan mounts in your case in those locations you can take a Dremel or something and cut a hole for the fan to intake through and some screw holes to mount it. You may also want to take some medium-fine mesh and place it over the fan holes to catch larger dust bunnies and stop stuff from getting caught in the fan blades.

For a decent CPU heatsink, if you just want something on the cheaper side that will keep your CPU cooler and run quieter than the stock fan, I recommend the Arctic Freezer Pro 7. If you're going to be doing overclocking, or really want a cool CPU, the Zalman 9700, Zalman 9900, and Thermaltake V1 are all excellent heatsinks.


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## typsu32 (Aug 2, 2009)

on the side of the case there is a mesh pad that i was planning on mounting one of my 80 mm fans to. 

the system temp keeps getting hotter and hotter. guess i need to look into putting more fans in it


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## Phædrus241 (Mar 28, 2009)

That would be a good idea. Definitely mount fans wherever you can. Remember, optimal airflow is as such:

Intake: front, bottom, side
Outtake: back, top, *sometimes* upper side
And the outtake should always be slightly greater than the intake.

If the side mesh is over your CPU and you have a heatsink that blows air straight out from the CPU, like the stock fan or Arctic Freezer Pro 7, then you'll want that to be an outtake. Otherwise, if it's over your GPU, or if the heatsink has the fan mounted perpendicular to the board, then you'll want it to be an intake.


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## typsu32 (Aug 2, 2009)

The system is running great. I still have to mod the case to put more fans in it. Thanks for all of your help. 

Just a couple more questions. How would I hook up more fans. I'm using all the connectors on the board for the fans. Is there some i can use from the PSU?


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## jolancer (Jul 5, 2004)

Might wont to look into a fan controller... then it will have all the ports you need right on the controller. and you will beable to controle there speed depending on your system load.. it makes it quieter at idle... and some of your case fans you dont even need pulling full 12v anyway.

http://search.store.yahoo.net/cgi-bin/nsearch?catalog=svcompucycle&query=sunbeam rheobus
http://search.xoxide.com/?query=sunbeam+rheobus&x=12&y=13&vwcatalog=xoxide

Those are links to 2 great places i use to buy parts from... linking to "Sunbeam Rheobus" Search... Thats the best fan controller iv ever seen. It allows full Volt range from OFF 0v to 12v, and the LEDs change collor at 7v witch is a safe booting voltage to make shur the fans have enough juice to start spinning from Off mode... i had the 4port but it appears they now have a 6port 'extreme' version aswell.

and that budget cooler that Phædrus2401 linked to looks realy good aswell... just fyi in my own testing... iv found conserning heatsinks its not about how much volume of air(size) that a fans HSF can move to cool it, but how close it is(Mount it Right on top) and the speed/volocity it can produce for higher WindChill directly on the Heatsink. 

note the tempature inside and out of your case will affect temperatures, a computer in a hot environment will run hotter. so dont worry about matching some peoples drastically low temps.


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