Windows 7: Recently started overheating CPU/crashing

Hi all,
My main PC recently started running slow. It had been perfectly fine the last several months(6-8?). I made sure my Security Essentials and Malwarebytes was up to date and did full scans, and nothing was detected. I looked in CPU-z and it showed my core speed of my i5-750 as being around 1.2 gb, fan was spinning around 1900 RPM (stock cooling). HWmonitor showed my proc at 89 C. While I was messing with it it powered off altogether.
I opened the case and everything looked fine, not much dust, fan spinning freely. When I powered it back up it stopped during post saying "overtemp CPU, press F1 to continue?"
I am not sure what else to check really as it just started happening. Is it possible the thermal compound dried up ? Should I just get a new heatsink/fan? Any help appreciated.



Thanks!

Hello Mate,

I had the similar situation turns out to be there were lot of dust between the Processor and Fan. Just remove it make sure you dust it out completely. Because that small grill structure will have lot of dust which might not be visible without taking out the Process fan. To be on a safe side apply Thermal compound. See if that fixes it.

Hope this helps,
Captain

Most likely one of the clip pins that holds the heat sink to the board came loose.

In this situation you have to remove the heatsink and apply new TIM then carefully replace the heatsink making sure that the pins are secured firmly with even pressure all the way around.

OK, thanks for the help both of you. OK so I pulled everything apart, and yes you were right about dust bunnies on the underside of the heatsink I couldn't get with normal maintenance vaccuuming. So I vaccuumed everything and used compressed air to thoroughly clean everything.
When putting the heatsink back on I noticed it wasn;t going on right, sure enough one of the white plastic clips was bent and when I tried to push it back down I bent it further. I thought I was able to get it bent back into shape and managed to get all 4 to feel like they seated. They all clicked in. But on bootup it is still hot. So I think I will run to Frys and grab a new one. I'll report back. Thanks again.

Ok, went to Fry's tonight. Got a $14.99 CoolerMaster heat pipe heatsink with fan, much better design it appears than the stock heatsink. PC is back the way she used to be. THANK YOU!

Glad that you got it work !

Yes those clips sometimes don't work so well. I'm glad you got it working Desslok.

Yeah I looked at the stock heatsink, sure enough the white part of the clip, one side was spread out and flattened so it was keeping one of the clips from seating all the way, and the arctic silver didn't spread to that corner of the proc. I'll try to take a picture of it when I get home, maybe it will help somebody else.

edit: added picture