I've been having some issues with re-fitting a CPU fan the past couple of weeks, previous to removing the fan its been hard work getting it to spin at anything above than 35%, since removing it its been difficult to get it below 100%. I've applied TIM in the 3 most common methods (dot, line over the dies, and spreading it manually) and none have done anything helpful.
Every time I've taken my HSF off after applying paste, only one side of the contact has any TIM on, my initial thought was I was screwing the fan on incorrectly, so I took more care to turn each diagonal equally, still the same issue. By this point I was rather annoyed and decided to apply the paste to my heat sink instead, spreading it out myself quite thin I attached it back to the PC, booted into the BIOS and to my horror I was running at 87c on bootup, it soon shot to 90 and I soon unplugged the power. After removing my fan I noticed that there was no TIM on the CPU, not something that should happen if the HSF was screwed in to full hand tightness. I applied more TIM to the heat sink, layering it up so it wasn't so thin, temp dropped by about 4c but was still stupidly high, after removing the fan the same issue, no paste on the CPU. I then applied some directly to the CPU, so I had some on the CPU and fan now, re-attached, got about 2c less than last time, took the fan off and a small ridge was visible on the right of the CPU where the fan had touched, but beyond that there was nothing. In my attempts to get a PC that I wasn't fearing at boot up I've had to lather TIM onto the CPU (waaaaaaay more than I would ideally use) and thats giving me around 50c idle, and over 90c loaded.
I'm sporting a Core 2 Quad (Q6600) on socket 775, my fan isn't stock Intel but I couldn't tell you what it is, its got screws and apparently no clips, and worked fine up until I was forced to remove it. I have been cleaning all old TIM off each time I've applied some new. My grease is cheap nasty stuff as that was all I could get, I've been looking to get some AS5 but I'd rather not get it if its not going to help my current issue.
I'm just completely lost what to do, is there some trick to getting the HSF to touch the CPU, or is this a lost cause and I should just get a better fan?
In any case of fitting a heatsink I would reccomend doing it outside the case if you aren't already.
By the sounds if it, Its a screw on heatsink+fan, In that case it should have a backing plate which will go on the back of the motherboard, Make sure that is aligned correctly with the 4 holes or the screws will just be turning and not actually screwing into anything.
Thanks for the reply, I was pretty sure it wasn't an issue with the backing plate, but seeing as this is a shelf bought PC and not a custom built one I decided to humour you anyway and check it out. I was right and its not a backing plate issue, however I did notice that my heatsink has a shorter side (something which I couldn't see properly inside my dark case), it turns out that I'd attached it wrong and a transistor was in the way of the heatsink, after rotating around I'm getting a nice 40(ish)c idle, and 55(ish)c load, all tested with RealTemp and Prime95.
Now I've solved the issue (ahem, my own stupidity ) I'll be ordering some AS5 as its supposed to be better, and I could do with a new tube anyway for my next self build.