cpu overheating on latitude c840

maynard99,

 

With one fin broken on one of the fans, you can lose as much as 50% of the air flow which would be generated by that fan.  The fan will also be louder since it will be off balance.  You may even be able to feel the vibration caused by the damaged fan if you are holding the system on your lap.  I would not hold it there very long, however.  The fan assembly can be replaced without having to replace the system board or the heatsink assembly.  The Dell part number for the dual fan assembly is 6F858.  Dell spare parts should be able to sell you this item.  Replacing it will require disassembly of almost all of the system including removal of the system main board.  Instructions can be found here.  Be sure to click the link for "Remove the system board" before you begin.

 

 

maynard99,

 

When you disassemble your system to replace the cooling fans, be sure that there is not dust cloggin the fins of the heatsink assembly.  The fans draw air through these and, even if the fans are clean, if the fins are cloggled with dust, you will not get the temp reductions that you are looking for.  Also, check the adhesion of the heatsink assembly to the CPU.  If the visible portion of the thermal grease around the edges of the CPU are cracked and dried out, consider cleaning the old grease from the top of the CPU and replacing it with new thermal grease.  "Arctic Silver" is a commonly recommended brand of thermal grease on these forums.

 

Steve

Thanks,

 

I've ordered the part, and should know by next weekend if my laptop runs cooler, and quieter.

Hi,

 

Make sure you are sold the correct fan. The C800 and C810 used a similar but less powerfull fan, it looks the same and was sold by some suppliers as a C840 fan.

 

                                                                      Regards Chris

Also if you still want your laptop to run cooler, download i8kfangui. It is a excellent tool which you can control the fans.

 

Do a google for i8kfangui.

Another simple yet very awesome suggestion to help your system run even cooler is simply to get one of those USB-powered laptop cooling pads.  They draw air away from the bottoms of laptops, further reducing the heat stresses to the units. 

 

I got one for my C840, and I swear by it!  My cooling fans inside the unit don't run as often, and after a few hours use, you can feel the underside of the laptop and it is barely warm!  These babies really work!  An excellent augmentation to the other suggestions for keeping the fans/heatsink fins clean, etc.

 

I hope that this helped!

 

Regards,

 

Bill