CPU Overheating

[AdvWar]

My i7 920 has worked mostly fine for over 3 and a half years, but I've started having some major heating issues. At idle, the CPU is at around 70 degrees, rising to 100 degrees when playing games. This results in the processor either under clocking itself, or just switching itself off.

I've tried reseating the processor, reapplying thermal paste, cleaning out the case with no change. The heatsink pins are properly secured.

Could this be a motherboard/CPU issue, or it definitely my heatsink?

[kalniel]

I'd say heatsink/fan. If you've cleared out dust from the fins and it's still a problem check than the fan is working OK.

[Phage]

+1 hsf.

[flearider]

3 yrs fan on heatsink going .. check rpms ..if it's not the fan ... hmm what paste did you use and how much went on ?

[Bonebreaker777]

Aye heatsink not exchanging heat with the surrounding air correctly/fast enough or the fan not doing it's job properly by providing the required amount of air.
What cooler you have?-cause if you are capable to exchange thermal paste I am sure you would notice excessive amount of dust accumulated on the heatsink and would take action to correct the situation. Thus could be a failure in the structural integrity of the heatsink (tho can't imagine how) or the fan itself.
You haven't changed fan monitoring settings in the BIOS recently nor installed fan controlling software? If neither then your fan needs replacing I would say. Or as a temporal solution a drop of silicon oil can do miracles.

[AdvWar]

Think I have got it fixed - on the mounting bracket for the heatsink, one of the screws was slightly loose, and tightening this seems to have restored temperatures back to normal.

Thanks for your help.

[carvedeye]

Think I have got it fixed - on the mounting bracket for the heatsink, one of the screws was slightly loose, and tightening this seems to have restored temperatures back to normal.

Thanks for your help.

I would still take of the HSF and clean it and add some new thermal paste to it as well, I would recommend something like arctic silver and your temps will improve even more

[Pob255]

Not really, as has been shown more than once applying the correct amount of paste has more effect than the amount of paste used.

If you're reseating your cpu then you should replace the paste and if you've not got any then getting some arctic silver or a similar good paste would be a good idea, but if you've already got decent paste you don't really need to buy more.

For full cleaning a heat sink which has been removed from the motherboard, remove the fan then clean it in a sink with warm water a drop of basic washing up liquid (the value green stuff not the fancy ones, they can leave residue) and a clean paint brush to work between the fins.
Towel dry the worst of the water off then leave to air dry.

[Bonebreaker777]

Saliva plus kitchen towel usually removes quite a lot as well :-)

[kalniel]

Saliva plus kitchen towel usually removes quite a lot as well :-)

Enough about your CPU licking habits

[Output]

Enough about your CPU licking habits

Bonebreaker777 is testing an upcoming Intel CPU... Lickwell.

[Pob255]

Saliva plus kitchen towel usually removes quite a lot as well :-)

your tongue is going to be a bloody mess if you try to get the dust out from between the fins of a cup cooler.
I meant for a good full clean not just cleaning off the base, and even then you shouldn't use spit way too much bacteria.
Full clean isn't that needed, it'll not hurt though and can be needed if the pc is in a cigarette smoker environment, as you get tar build up (often incorrectly called nicotine staining) this leaves both the surface and dust sticky, you cannot blow that off with compressed air or brush it off, you need to wash it.
(interesting side note, e-cigs don't leave any tar they will produce extra dust but it's a very fine powdery dust which can be cleaned off with compressed air or brushing)

For cleaning the base,
First scrape off the worst of the old paste with a wooden cocktail stick, ridged enough to make a good scraper, soft enough not to damage the metal.
Next clean with kitchen towel and isopropanol or vodka.