- This topic has 2 replies, 2 voices, and was last updated Dec 8-10:16 pm by ModdIt.
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ModdIt
A few days ago I setup antX 21 on a Bin Box, a small form PC which had run at least 10 hours a day for years in a doctors practice.
Noticed slow running and either no fan noise or Big modern Turbofan on Takeoff thrust style noise.
DISCONNECT POWER… Open case, take a look. The fan was not spinning on switch on so disconnect all cables and off to my desktop.
In this case it is crowded, the Power supply (PSU) is a special small form factor device, it is partialy over the CPU fan
A very flat fan is fitted so no spare at hand. Removed the fan, a 3 pin type, checked the label. Lucky it says SLEEVE BEARING.
Cleaned the fan carefully with a soft brush, sucking away the dust with a vacuum cleaner, if you have none go outside.
Carefully peeled up the label on the rear of the fan to expose the spindle and bearing. Two choices now, dissasemble or just lubricate.
Dissasembling involves removing a spindle retainer, often a small plastic disc which sits in a groove on the spindle, then lifting off
the rotor. In many cases ther is a thrust washer on one or both ends of the bearing, they are tiny, do not lose them.
Use a tiny drop of oil to lubricate the rotor, a drop on the tip of a toothpick is fine. This is an old fan,
Often silicone oil is recommended, I used what I have, sewing machine oil, as it (the fanassembly) will be replaced if it gets noisy again.Ensure the cooling fins are clean, that includes taking a look in the PSU, DO NOT poke anything metallic or conducting through the cooling
holes on a PSU !!!!. If the PSU is dirty inside but not greasy muck you can hold the internal fan still with a small stick and try and gently
blow out the dirt.If it is really dirty take it to a TV repair Shop and ask them a price for opening, cleaning and check capacitors for swelling.
In many areas it may be cheaper to replace.
DIRE WARNING: The High voltage Capacitor or Capacitors hold energy for a long time, enough to kill you in an instant !!!!.I have on occasion replaced caps, I am extremely careful to discharge the High voltage ones using a resistor taped to a dry stick,
I then can carefully solder a resistor over the terminals to keep them shorted for the repair duration. Again everything used must
be insulated. Hold the solder wire or tape with an insulating tool, capacitors are nasty beasts which can carry something known as residual
charge.If possible replace the PSU, it is safer.
Reversed the proceedure, closed case and ran the box ,hard, a remaster of a live stick is a fine test. CPU Temp was fine, fan running quiet.
I used sensors command should that not work do.
sudo apt install hddtemp lm-sensorsOn a laptop the proceedure to fix fan issues is way more difficult but also more critical as overheat will kill the device over time, it
also is a major performance killer. Partial cooling causes CPU and GPU to throttle, if you are lucky…. Some components will just burn out
especially voltage regulators.Will post on laptop cooling system clean with illustrations sometime soon. I do not reccommend poking through cooling holes, the filth
stays inside the device, full cooling is not restored and any partial success is short lived.- This topic was modified 1 year, 5 months ago by ModdIt.
Robin
Many thanks, @ModdIt for this detailed description. I had planned to write a guide like this long ago myself, but never found the time to make it real. So I’m glad you have covered this important theme now.
Let me add some remarks I found good to know on some devices.
1.) You might find under the sticker an additional plastic stopple instead of the expected hole with the end of the spindle. It seems at first glance there is no way to reach the spindle, but this is not true. You’ll have to find the (nearly invisible) border of the stopple and prise it out of the hole in which it is pressed in, using a small blade. Then you have clean access to the end of the spindle.
2.) You might find a metal snap ring sitting in the notch of the spindle end, and you’ll have to carefully widening its gap in order to make it slide over the spindle. There exist special pincers for this, but you can use a tiny blade of a screwdriver also for this. When remounting make sure this tiny snap ring sits clean in its notch. As Moddid mentioned, if there are any additional washers, make sure not to lose or destroy them. They have to be in their original position after remounting.
3.) In case the fan wheel wouldn’t move at all, don’t pull at its fan blades. This will damage the device. Instead, press the axis from behind using a small thorn after you have removed the snap ring. You will find resinified old lubrication. Clean the spindle and the inside of its bearing carefully, using a small wooden skewer, wrapped with a thin layer of cellulose fiber fleece, soaked with a drop of fresh oil. Make sure to remove all the resinified old substance, but never use an aggressive solvent which will damage the device.
4.) Make sure the oil type you use doesn’t corrode the plastic on long term. I’ve seen plastics embrittled by some types of sewing machine oil after few weeks already, even if the oil was classified as “resin and accid free”.
5.) When reinstalling the freshly cleaned and lubricated fan unit make sure it blows the right direction. The warm air stream should go out of the housing, not the other direction. (It probably will be mountable in both directions without notice.)If you do a good job here, you won’t need to buy a new fan even after 20 years. You can decide whether you are going to buy a new fan every 2-5 years, or put a drop of oil into it at the same intervals. It doesn’t cost more work to go and buy a new one and replace it, than to refresh the lubrication in the existing one. But it saves natural resources. And using the correct type of oil it will run as silent as a new one for the same period of time again.
In order to give you an idea what will expect you when giving this procedure a try, I’ve attached some photos of the process. You can see clearly the metal snap ring. In heavy duty fans of high production quality standard you will find these metal snap rings instead of plastics, and also the plastic stopple instead of a sticker only. These devices are worth to keep, they will last much longer than a cheap china replacement you get nowadays even when buying in a specialised store.
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Windows is like a submarine. Open a window and serious problems will start.
Thanks robin, very good and detailed input, any ideas on safe oil, tribology (sorry Lubrication Technology) is a difficult subject with high RPM high hours and often raised temperature from nearby components. As you wrote better fans, usualy those with porous bronze bushings can outlast the computer they are fitted in. Time to clean and lubricate is in my experience less than that needed to source a correct replacement and I also prefer repair or upcyle from other defective devices to trash can.
Laptops have tiny very specific high pressure high flow fans, most often ducted and running in front of a heat exchanger, the end of a heatpipe or pipes.
I can add a few detail pics of some internals shortly. Probably while cleaning a thinkpad T series.Notes for followers.
up to now I have used OW30 Synthetic modern car oil, some sewing machine oil from a bottle with no label, bone oil. All those fans are still running, for how long, I have to wait and see. On bronze bushings the car oil is adequate but not ideal for small fans, as a multigrade lubricant it thickens as temperature rises. I would not use it on plastics.
Ballistol, is good for cleaning but crazes some plastics so not recommended. WD40, is a preservative not a lubricant so for usage case not a good idea, please do not use it for cleaning, porous bearings will hold it and later destroy your freshly added lubricant.
Last fan I did was 40X40X10 mm, the smaller the fan the more difficult.One repeated caution. for anyone who has problems and opens a Power supply, Please be very careful, the big black capacitor front in the pic Robin provided can kill in an instant, they have a nasty problem, you can discharge them but they have a phonomena called residual charge. I recommend to short them with a resistor for the duration of repair whenever possible. You should not think black rubber garden gloves or similar houshold gloves offer protection, they almost always contain enough carbon for a 400 Volt even partialy charged cap to create a current path to your hand. Electricians wear dry special insulating gloves with a safety rating printed on them, and stand on an insulating mat, wooden workbench is ok, metal never.
I am lucky to be alive, sweaty hand, no glove and 40 Volts from a stick welder, I had irregular heartbeat for days, and beat my head on a wall for being so stupid, despite a lot of training.
- This reply was modified 1 year, 4 months ago by ModdIt.
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