CPU fan struggling to turn

[Mattayus]

Got a blue-screen from an overheated CPU yesterday. I opened up the case and saw the fan struggling to turn. I took it off, cleaned it, blew all the dust out, and gave it a wriggle. That seemed to work.

I boot up again this morning and it struggled to turn again. It turns, but reeaaaally slowly. After a wriggle and a kick-start (helping it spin by hand) it started going fine again.

Clearly it's time for a replacement, but what causes this shit to randomly happen? Also, is there anything specific to consider when buying a replacement? (since I've never had to replace one before!)

 

[Empathy]

Could very well just be a mechanical fault. If you move your tower around a fair bit you that might be a logical cause.

If you're going to replace it, there are plenty of options in regards to performance / noise levels. These days you can buy amazingly effective water-cooled heatsinks for ~$100 that work pretty much flawlessly. Being in the audio industry, you might want to look at one of those for what is an almost entirely silent cooler.

 

[Mutant]

Replace it ASAP or you will have to buy a new CPU.

You just have to tell the sales clerk what type CPU it is and he will know what type of fan/heatsink you will need.
There are different CPU slots and sockets which will require different type heatsinks or some converters.
Mine is an old AM2.

Of course you can save few bucks by just buying a fan of the correct size.

Oh and one more important thing: make sure that the new fan/heatsink will fit there without blocking the gfx card or a hdd... some are very large, especially these new silent ones.

 

[Mattayus]

Awesome thanks for the help dudes!
When putting the new one on will I need a new dab of thermal paste?

 

[Empathy]

If you haven't overclocked, thermal paste isn't really necessary. You can certainly go ahead and put some on if you want, but it's not going to have any huge impact if you're running stock speeds.

 

[JBroll]

I'm not sure about that - you'll want some goop to help the cooling device draw heat evenly. You won't need to throw serious money at the fancy stuff made out of kitten tears and such, but (unless the device comes with some material already on it) you'll definitely want to have something available. The shop technician will be able to tell you if you have to pick anything else up - your processor will stop being a processor fairly quickly if the heatsink can't perform properly, and lack of thermal goop will help that happen.

Jeff

 

[kvoid]

If you haven't overclocked, thermal paste isn't really necessary. You can certainly go ahead and put some on if you want, but it's not going to have any huge impact if you're running stock speeds.

Nah bro.

No thermal compound=goodbye CPU.

Remember to scrape as well as you can any remaining residue from the cpu before applying new Thermal Insulation Material. Get some Arctic Silver or such.

I personally use the Noctua TIM that came with my very awesome NH-D14.

However, I understand most of you wouldn't be interested in such excess. I don't overclock, I just like my CPU to last a while, and be silent

I presume there are quieter options though.

As to why your fan died, well, if you don't lube em a little with sewing machine oil or the like every six months, they'll run dry and grind to a halt. This of course depends on the bearing, whether it's a sleeve or ball, or as in my case (Noctua) sealed so you can't do a thing about it either ways.

 

[Soundlurker]

Some heat-sinks have thermal paste pre-applied. If yours doesn't than you do have to apply some.

 

[Mutant]

+1 To no overclocking = no need for any paste (19 years of personal experience building PCs from parts).
You just need to make sure that the heatsink will be touching the CPU as flat as possible.
The paste usually makes only 1 to 2 degrees Celsius difference.

 

[EerieVon]

Clearly it's time for a replacement, but what causes this shit to randomly happen? Also, is there anything specific to consider when buying a replacement? (since I've never had to replace one before!)

It happens, the components just wear out--like anything that works that hard or so often. Its not like most fans are made from quality components. I check mine once a year.

 

[JBroll]

+1 To no overclocking = no need for any paste (19 years of personal experience building PCs from parts).
You just need to make sure that the heatsink will be touching the CPU as flat as possible.
The paste usually makes only 1 to 2 degrees Celsius difference.

Even if the heatsink is sitting as flat as possible, manufacturing imperfections will mean that some areas won't have proper contact. This plays hell with the processor, and I can't see why someone would skip such a simple and cheap step anyway.

Jeff

 

[MindMunch]

I would never put a heatsink on a CPU without cleaning both with isopropyl alcohol and applying a new layer of thermal paste first.

 

[EerieVon]

Even if the heatsink is sitting as flat as possible, manufacturing imperfections will mean that some areas won't have proper contact. This plays hell with the processor, and I can't see why someone would skip such a simple and cheap step anyway.

Jeff

Exactly..not like thermal paste is that expensive

 

[TheWinterSnow]

Back in the day I had a Pentium 4 that I experimented with in terms of cooling (years ago before I built my first computer) and with thermal paste it ran about 40C and without ran about 65C. Moral of the story, thermal paste makes a huge difference, and its cheap. Just make sure you don't put too much on.

 

[Damian B]

Thermal paste is important, don't skip it. Most retail heatsinks come with thermal paste already applied, though the higher-end ones don't because they expect enthusiasts to buy the expensive stuff. Make sure the heatsink/fan you buy matches the socket type of your processor and you're good to go.

 

[sprack]

P4's were up to 200W processors. Horrible architecture.

We have boxes of the Gelid grease for the labs. Arctic Silver is just as good. Use them in the air-cooled and peltier's. It's essential for modern processors to make good contact with the heatsink. What it won't do is kill the processor. Anything made in the last 5yrs has a thermal diode in the chip that prevents a thermal run-away condition. If the proc reaches 120C it will shut off the system, its called ThermTrip. We run thousands of cycles on processors in this state to make sure the process works, diode are properly calibrate and integrity is kept.

That said if a proc is near 80-90C it will throttle itself regardless of whether you have power-management disabled in bios. You will also never get turbo-mode in hot conditions like that. Spend the $5-10 and grease it, just a thin layer on the die between it and the heatsink.

 

[SimonSez]

Sometimes with a fan like that you can try peeling off the label on the middle of the fan, there should be a hole there and you can put in a drop or two of oil and then cover the hole with tape. Run it for a while and see if it starts running normally again.

I usually buy Scythe fans, they're quiet and I have a couple that have been running 24/7 since 2002 and are still working fine. Noctua fans are good if you want a really quiet fan with lots of airflow.

 

[Mutant]

Even if the heatsink is sitting as flat as possible, manufacturing imperfections will mean that some areas won't have proper contact.

Correct.

But paste will make a big (up to 25C) difference only when the heatsink is installed by a noob and doesn't touch the CPU.

Yeah i had such cases... a customer summons me and complains about his newly built PC smelling like it burns and turning off a minute after booting up.

The first and the last thing i do is i reach into the case and whiggle the heatsink a bit without even detaching it.

The PC powers up and works... i download SpeedFan and check the temperature, the customer goes like "whoooaaa ! how ???" and me "that would be 25 Zl (about 8 USD) for my time" hehehehe.

Even when installed properly, but with poor quality heatsink, the paste will make about 15C difference when under 100% load.

It works by pushing out micropockets of air that act like little pillows between the CPU and the heatsink, so when the heatsink is polished to high shine (like a mirror), there are only very few such pockets of air and applying the paste in such a situation makes a very tiny difference.

Of course i am not telling you to not to use it, only stating some facts.

Currently my clean CPU in a PC situated close to a turned on room heater, near a window, runs idle 40-45C and under 100% load 60-65C and i have it set in BIOS to give me a sound warning when the fan fails and power off when it goes above 80C.

From my experience applying the paste to my PC would make the idle temp go down 1-2C and lower 100% load temp by maybe max 5C, but i just don't want and don't like to make the CPU dirty to increase its life by maybe few months, my fully informed choice.