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Mission Cooldown: Reign in on the burning Hellforge! [Aka: How I cleaned up the crud off my CPU heat sink/fan]

··1254 words·6 mins

It’s been about 4 years since I built Hellforge. It’s gotten some updates:

  • Replaced Gigabyte 7750 with an Asus Strix 970
  • Added on a Samsung Evo 840 256GB
  • Memory upped to 16GB
  • Replaced the Logitech K210 keyboard with a Corsair K70 Lux RGB
  • Replaced the CM default case fans with Bitfenix Spectre

But the one thing that has remained constant: the CPU heat sink and cooler. My old house was dusty and no matter how much I cleaned, within a week or two there’d be quite a lot of dust. I did a  bit of superficial cleaning on the insides but never bothered cleaning the CPU heat sink/fan.

The hesitation comes mainly because I had a torrid time when installing the heat sink the first time and didn’t want to damage it. Off late the processor’s been running hot and the CPU fan’s been on overdrive pretty much all the time. Last week I was curious about the temperatures it was running at and HWMonitor - I wasn’t prepared for this.

Basically the temperatures were close to Tj Max and I wonder how come the CPU wasn’t throttling. With temperatures at this level, I had to do something about this. And egged on with support of Alpha, I decided it’s time to clean it up.

Here’s what I bought to clean up:

  • Compressed air can -  A blast of this can get a lot of dust off but you need to keep this straight, so difficult to use this for hard to reach surfaces
  • Hand pump - really useful for the hard-to-reach surfaces which can’t be reached above
  • Isopropyl Alcohol - You’re going to use this to wipe off the remaining gunk off the heat sink and the CPU.
  • Some tissues/cotton swabs to clean up the gunk
  • CoolerMaster MasterGel - I settled on this after extensive discussion with Alpha. He suggested to get the cheaper one, since the higher priced version is more suited for overclockers

Now, for the pictures. You’ve been warned. This was how it was when I opened the cabinet

CPU heatsink/fan with cabinet top fans

Full cabinet

CPU heatsink/fan with cabinet top fans

Full cabinet

Getting the heat sink out was far easier than expected. Just had to turn the notch in the direction of the arrow and give it a gentle pull. You can see how much of crud has collected over the past 4 years





The compressed air can came in really handy here to clean up the heat sink and fan. Using the hand pump would have taken forever to clean this up and not to forget give you RSI. Unfortunately I didn’t take a pic of the fan after the clean-up, but I did make it squeaky clean.

Now that the fan was all clean, time for the heat sink. Here’s the remains of the previous TIM.

previous thermal paste

previous thermal paste

Next, cleaning this was pretty easy - just take some tissue paper/cotton buds, dab them with isopropyl alcohol and wipe them off. 

previous thermal paste

So after cleaning up this is what we have

Cleaned up CPU heat spreader

Cleaned heat sink

Next, I applied the thermal paste as CoolerMaster described on their site.

thermal paste spread out

Now this is where my problems began. I tried to put the heat sink back on and while it slotted in fine, I didn’t get the distinct ‘click’. I moved the heat sink to confirm whether it had fit in tight - yeah that didn’t happen. After multiple detach-attach sessions(and an hour of fiddling with the notches, pillars and what not), I still couldn’t get it fit in properly. When I flipped the heat sink around, I realized that one of the prongs had bent away.

I straightened it out, realigned the notches and tried again.. to no avail. By this time I was frustrated and had run out of time(I had guests coming over) so I left it as is and decided to relax for the evening

Few hours later, I decided to try again, and this time I thought I got it right. The heat sink seemed to have no slack, so I connected the power supply and the HDMI cable, booted it up, launched the HWMonitor and was expecting it to be all ok - only it was not. Disaster.

Crazy temps

102+ degrees on idle, zero workload and by the way the cursor was responding, there was no doubt the CPU was being throttled. Disconnected everything, moved the heat sink slightly - and it came out. No wonder the temperatures were that high.. I gave one last ditch attempt but failed again. But as an experiment, I pressed the fan tightly against the CPU to see if that would yield to any change(just to confirm the high temperatures were because of heat sink not fitting in tightly) Surprisingly there was no change in temperatures.

By this time it was late into the night, I was tired and I just decided to head to sleep. Just before I slept off, I saw a video on the heat sink installation and realised I was doing a small mistake, but by then I had already removed my lenses so decided to just sleep and check it the next day.

Yes, I turned to good ol' Linus' video for help and a sentence he mentioned - “Turn the notch towards the arrow for removal and away from it for installation” - is when I realised what I was doing wrong - I hadn’t turned the notch after removing it and was making installation hassle. Once I did what Linus mentioned, installation was a breeze and the heatsink was fixed, tight and all good to go. Or so I thought. Booted the system - only to find the temperatures were still in high 80s. One step forward, two steps back.

However, given that the heat sink is seated correctly now, the fans were rotating, it could mean that either too much of paste was used or it was not spread evenly. I removed everything and decided to re-apply the paste. However instead of spreading it across, I decided to use the “pea” method - basically you drop a blob of the paste at the centre of the CPU and you rely on the pressure being put when the heat sink is mounted to spread the paste evenly.

Paste on CPU heat spreader

CPU Idle Temperatures

Success! Wanted to check how high it would go on load. Downloaded and started AIDA64 and started a CPU stress test. And the temperatures were not too shabby. Also, the CPU is finally silent(although I do have a custom fan profile - but that was in place before the clean up).

AIDA64 CPU stress test

Suffice to say, I’m happy with these for now. Huge thanks to Alpha for guiding me throughout this and bearing with my incessant questions

Check this article on How to correctly apply the Thermal Paste.