I have this old AT PSU that is definitely very much still alive and functioning, but the fan doesn't move at all. If I nudge it in one direction, it might manage one or two revolutions, but then it stops again.
Is it advisable to try to clean these? How exactly do you do it? Or should I just give up now? (Stories of the gigantic voltages lurking within an opened PSU are alarming.)
replace the fan is the best option, provided it is a quality power supply.
As for the "gigantic voltages inside", its really not that bad. Do what I do.
1: Put the power supply under load. Preferable a heavy load.
2: pull power plug
3: ???
4: PROFIT!!!
No more worries. If you are REALLY paranoid find the largest capacitor, and short its terminals with a screwdriver. NOT while its plugged in.
It is a mistake to think you can solve any major problems just with potatoes.
Ive done it several times and it works. I would cut the wires and remove the fan completely from the PSU to work on it. Opening a PSU to remove the fan is pretty safe as you do not even need to touch the PSU PCB.( In any case Just do not touch the leads from the big caps in the PSU and you wont get shocked )
At this point you can also simply change the fan but seized fans can be cleaned.
Ive done it numerous time with lubricated contact cleaner. Some people have done it with WD40 i hear but i prefer to use the product that is designed for this.
You apply a generous amount of lubricated contact cleaner in the fan motor and you move it around by hand, occasionally applying more contact cleaner until it moves freely. It can take a while if the fan is very stiff. You should test the fan before re soldering it in the PSU.
Sometimes a resurrected fan ends up too slack and becomes noisy. When this happen I usually change it.
FM sound card comparison on a Grand Scale!!
The Grand OPL3 Comparison Run.
I'd discard that old tired dirty fan and put in a new one. Better don't gamble here, if PSU fan stops, PSU fries, sometimes screwing part or whole system.
Most probably it's a standard 80x80 fan, cheap and easy to replace. If there is a header just plug the new fan in. If there isn't a header, and the old fan wires are soldered to the power supply PCB, you'll either have to cut and solder the new fan wires, or route them out of the PSU to some molex connector, or mobo fan header.
Here is a tutorial.
Even cheap crappy PSUs have bleeder resistors on the main caps, so even if there's a fault in the PSU, it'll still drain the charge pretty quickly. Most PC PSUs are perfectly safe within about 20-30 seconds after being unplugged... and it generally takes a couple minutes to get all the screws out and get the cover off, so even a PSU with especially gigantic main caps will be safe by the time you can actually take it apart.
Fans can be resurrected, sometimes just with a cleaning/relube of the bearings... 3-in-1 oil is about ideal, and remember, WD40 is NOT a lubricant... or worst case it's often possible to replace the bearings. However, the former option tends to be a short term patch... if the bearing is damaged, you might can get it spinning again, but it ain't gonna be quiet. (And if the fan is seized, the bearing is damaged.) The latter option is quite tedious and is only worthwhile on oddball shit like proprietary laptop fans, where a replacement isn't available.
For an 80mm fan like you find in a PSU, just replace it. If you're lucky, it might just plug into the PSU board using a standard connector, and if you're not so lucky, you'll have to splice a couple wires... either way, though, it's not difficult, and 80mm fans are cheap, assuming you don't already have a box full of salvaged spares.
While your replacing the fan, I always take it a step further and cut the stamped fan grill out with a dremel and install a nice shiny one. Not only does this increase airflow but really help cut down on noise.
^Thats a good idea!
FM sound card comparison on a Grand Scale!!
The Grand OPL3 Comparison Run.
Bushwack's advice is a solid one, those stamped, flat and wide concentric rings grills are a crime for aerodynamics. Wire grills are much better:
Effects of Grill Patterns on Fan Performance/Noise
In the PSU we need some sort of grill for shock safety, but for the case fans we can cut out the grill completely and clear the way.
Let the air flow.
Let the air flow!
Take the PSU apart with AC cord unplugged of course.
Remove the PCB with the 4 screws.
use a several hundreds of ohms resistor with wires to the end to discharge any left voltage on the big capacitors, or leave it unplugged for several days or uplug ac cord indeed while running pc before taking it apart.
Replace the caps, especially the smaller 1000uf 2200uf filter caps.
Remove the fan and remove the sticker with heardryer and spray WD40 inside it on the bearing opening while rotating the fan on power or by hand.
Or better remove the holder ring and clean out by hand removing the two small bearings if there are any, most of that time they are indeed already noisy and time to replace as a whole.
Cleaning the fins works perfectly with baby wipes. 😀
Or better take a good 250w new type atx style and remove atx mobo power connector wiring and solder the AT mobo wiring in place.
Use green and black instead of 220vac power switch.
Take attention to what youre doing an measure volts for verification 3.3 5v and 12, -12v etc unconnected with only a Cdrom drive to the existing 4 wire molex plug.
Well, here's what I found underneath the sticker. I can see no obvious way of pulling the fan apart and getting to the spindle directly. Should I just throw some 3-in-1 down there and hope for the best?
It spins again on its own now that I've cleaned out some of the dust with compressed air, but it makes a fairly loud groaning sound.
No need to pull it apart, just a dab of oil and turn the fan by hand a few times then slop it all back together. That simple but lazy repair can last anywhere from a few months to several years depending on the use and the quality of the oil. A Q-tip and motor oil or a quick squirt of WD-40 is all you need.
On a far away planet reading your posts in the year 10,191.
wrote:Well, here's what I found underneath the sticker. I can see no obvious way of pulling the fan apart and getting to the spindle directly. Should I just throw some 3-in-1 down there and hope for the best?
It spins again on its own now that I've cleaned out some of the dust with compressed air, but it makes a fairly loud groaning sound.
Couldn't you just replace that fan with a current 80mm model ?
No matter where you go, there you are...
Amazing! It is deathly quiet now! It kind of makes me want to pull apart some of my other PSUs and give them the same treatment.
wrote:Couldn't you just replace that fan with a current 80mm model ?
As it is indeed hard-wired, I would have to cut the wires and re-solder them (or something), and I'd rather not get into that.
I can see no obvious way of pulling the fan apart and getting to the spindle directly.
Good that you got it sorted, but for future reference: The little white-ish nylon ring on the end of the rotor shaft... it's usually pretty hard to see, but it should have a split in it somewhere. Find the joint, spread it apart enough to pop the ring out of the groove in the shaft, and you can then pull the rotor out from the other side. But be warned, those little clip rings have somewhat of a tendency to go flying off across the room, never to be found again.
And I stated before, but it appears I need to say it again: WD40 IS NOT A LUBRICANT.
wrote:Amazing! It is deathly quiet now! It kind of makes me want to pull apart some of my other PSUs and give them the same treatment.
wrote:Couldn't you just replace that fan with a current 80mm model ?
As it is indeed hard-wired, I would have to cut the wires and re-solder them (or something), and I'd rather not get into that.
Fair enough, glad you were able to get the fan lubed up enough to quiet it down.
Too bad most PS Units have the old brass bushings instead of a ball bearing fans.
No matter where you go, there you are...
What I did with a noisy power supply fan is replace it with a case fan that takes molex power. Just cut the leads to the old fan, and leave the molex lead from the new fan hanging out of the PSU. Then just connect it to a spare molex lead. It's a good ideat to tape the connector so that you don't accidentally disconnect it. This way you don't have to worry about soldering, or finding a fan header inside the PSU.
I love the idea of replacing the fan grills. Unfortunately, my noisiest PCs are my tandys, where the grill is cut into the case. The collector in me doesn't want to alter the exterior of these classic PCs. But I am going to give this a try on my 486 and pentium.
Yikes... for years I've cleaned out PSU innards heedless and unknowing of the "gigantic voltages inside"! There but for the grace of God go I...
wrote:Yikes... for years I've cleaned out PSU innards heedless and unknowing of the "gigantic voltages inside"! There but for the grace of God go I...
It's one of those things I always thought was a big no-no, much like opening up a CRT and poking around inside.
When building a retro PC that I wanted tuned for quite, I ended up removing the fan in the PSU and replacing it with another standard one (the old one was soldered to the PCB). I removed the fan, bridged the divider, and installed a replacement. The replacement was meant to plug into a motherboard header so I ended up running the power cable through a little hole, connecting it to a fan controller, then to a header on the motherboard. Perfectly silent and easily replaceable if I need to do it again in the future.
I don't know if it was right to just bridge the gap with a wire. But I think I needed to do it or the PSU wouldn't spin up since it thought the fan was dead. Maybe I should have added a resistor?
