Borgholio
1 Copper

Dell Optiplex 960 - CPU getting too hot

I just purchased a (barely) used Optiplex 960 from my office (my employers often sell used equipment to employees if they want to get rid of it).  It's in great shape, clean, and all the hardware seems to work, except for the fan speed controller.  I know it's supposed to adjust the speed of the cooling fan depending on how hot the CPU is getting, but it's not doing that.  The fans seem to stay on low / medium speed even when the CPU is pushing 70 degrees C according to Speedfan...which is WAY too hot.  The only way I can get the fan to speed up is by disabling the auto-speed control in the BIOS and leave it on 100% constantly. 

Anybody have any suggestions?  Is the temperature controller damaged, or do these systems normally run hot?  Thanks!

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5 Replies
7- Thorium

RE: Dell Optiplex 960 - CPU getting too hot

How do you know 70ºC is too hot?

Do you trust SpeedFan with a Dell PC? The last time I used SpeedFan on a Dell PC , it said the CPU was running at several MILLLION degrees C.  I don't think so... 

You might need to remove the heat sink, clean both surfaces and apply a new thin coat of thermal paste, eg Arctic Silver, and then reinstall the heat sink.

Ron

   Forum Member since 2004
   I am not a Dell employee

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Borgholio
1 Copper

RE: Dell Optiplex 960 - CPU getting too hot

Hi!  I tested Speedfan on my non-Dell PC and it matched up exactly with what my motherboard manufacturer's utility reported.  If Speedfan isn't accurate for a Dell, could you recommend a monitoring utility that will work accurately?

As for the temperature, I was going by Intel's specs for that specific processor:

ark.intel.com/.../Intel-Core2-Duo-Processor-E8500-6M-Cache-3_16-GHz-1333-MHz-FSB

According to their specs, max temp is 72.4c so if this chip is hitting 70c then it's pretty close to the redline.  If Speedfan is showing the chip hitting 70 under heavy load and the fan hasn't increased it's speed, then it would seem that either Speedfan is incorrect and the chip is still far less than 70c, or the fan speed controller might be having issues.

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7- Thorium

RE: Dell Optiplex 960 - CPU getting too hot

I don't bother checking CPU temps any more.

If you think there's a problem, the first step would be to replace the thermal paste and re-secure the heat sink.

Ron

   Forum Member since 2004
   I am not a Dell employee

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Borgholio
1 Copper

RE: Dell Optiplex 960 - CPU getting too hot

Well I think there could be a problem with the heat sensor that controls the fans, not with the heatsink.  It's certainly worth looking at but I don't think that's the issue.

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7- Thorium

RE: Dell Optiplex 960 - CPU getting too hot

Yes, it could be a problem with the sensor that monitors temps, or it could be the sensor in the fan too. Replacing the thermal paste is probably easier and less costly to test before you look further.

Don't know if this Optiplex has a diagnostics partition, but reboot and press F12 to see if there's a Utilities or Diagnostic partition available, and run the fan tests.

If there's no Utilities/Diagnostics partition on the HDD, the diagnostics may be on a Dell Resources CD, assuming you have the disks for this system.

Ron

   Forum Member since 2004
   I am not a Dell employee

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