Failing PSU fan, need advice

[Crittias]

My wife has a Dell Dimension 8400 desktop computer, and the fan on her PSU is starting to fail. Every few days/weeks the fan will begin to emit a loud buzzing noise. So far my solution has been to tap the fan blades with the end of a plastic straw, which briefly slows the fan down and causes the noise to completely stop. Obviously this is not a good long-term solution.

Can I fix the existing fan? If not, how easy would it be for me to swap out the fan inside the PSU with a new one? Any advice is greatly appreciated.

 

[Billb2]

Fix the existing ...not likely possible.

Replace it......Depends on how handy you are.
Do you know:
Which end of a screwdriver is the business end?
Not to stick the business end into a live 110v outlet?
If you're confident that your answers to the above are correct, then you're good to go.

Remove the PSU, take off the PSU cover. Remove the fan, get the Mfgr and model no. (it might be under the sticker in the center of the fan). Google that and buy one online ($3-20 + shipping). Or, knowing the model number, you can find out the CFM (Cubic Feet per Munute) rating of the fan. Buy one locally ($2-10) that is the same size, CFM rating (+/- 20% would be fine), and has the same number of wires (2 or 3) to it's plug .
Reverse the disassembly process.
You did unplug the PSU, didn't you...hey, get up...somebody call 911...

If the computer is still under warranty you can call Dell, but that will take longer, and if it isn't warrantied, it'll cost more too.

 

[Crittias]

Thanks. I figured it was as easy as you described, but I thought it was worth asking first.

My wife will be out of town next week for a few days, so I'll have time to crack open her computer and find a replacement fan while she's gone. I'll post results then.

 

[gorobei]

i think most psu fans are two wire deals, and the speed is voltage controlled by the temp of psu. Does plugging in a three wire affect anything?

 

[mpilchfamily]

The 3rd wire, usually a yellow wire, is there for reporting the fan speed. Its not important and can be cup off the fan completely.

 

[Billb2]

Well, did you electrocute yourself yet?

 

[rich168]

my psu was puffing smoke before I discovered the fan wasn't turning anymore....

dead psu

 

[Crittias]

Originally posted by: Billb2
Well, did you electrocute yourself yet?

My wife leaves for Chicago Monday morning, so the electrocutions will begin then.

 

[MarcVenice]

Haha, can't wait I replaced my own fan too btw, I just stuck in a antec tricool, and I'm fairly certain it's on low, pretty darn quiet, doesn't move a lot of air though, and so far the PSU is still going strong, haha. First time I didn't put it in the right way though, and it was blowing air out, instead of into the PSU. Didn't electrocute myself though, which is a fairly big plus. I did have to remove the header from the OLD fan, and solder it onto the antec tricool, because just plugging in the antec tricool fan into a molex plug wasn't enough, apparently the PSU somehow thought there was no fan, and it wouldn't power on for more then a second.

 

[coolpurplefan]

Originally posted by: MarcVenice
Haha, can't wait I replaced my own fan too btw, I just stuck in a antec tricool, and I'm fairly certain it's on low, pretty darn quiet, doesn't move a lot of air though, and so far the PSU is still going strong, haha. First time I didn't put it in the right way though, and it was blowing air out, instead of into the PSU. Didn't electrocute myself though, which is a fairly big plus. I did have to remove the header from the OLD fan, and solder it onto the antec tricool, because just plugging in the antec tricool fan into a molex plug wasn't enough, apparently the PSU somehow thought there was no fan, and it wouldn't power on for more then a second.

I don't get it. How do you get a plug outside the PSU if the fan is inside? Did you have to drill a hole or something? (n00b question I guess)

 

[Zap]

Originally posted by: Billb2
Fix the existing ...not likely possible.

Actually very likely possible, especially on a fan that isn't quite dead. You need to peel back the sticker on the hub of the fan on the side that the wires go in the hub. There should be a rubber plug in the middle. Remove it and drip a few drops of light oil into it. Replace plug, replace sticker (or stick some tape over it) and voila! You've just extended the life of the fan. This will not make the fan perfect nor will it be a permanent solution. However, this fix does work.

If you're planning to keep the system for many more years, then do it right and get a replacement fan. If you think you'll be replacing the system within the year, then don't waste any more money on it and do the oil repair.

Originally posted by: coolpurplefan
I don't get it. How do you get a plug outside the PSU if the fan is inside? Did you have to drill a hole or something? (n00b question I guess)

You run it through the same hole that the other power supply wires go through. There's usually enough space for an extra couple wires, plus usually it is notched on one side to allow wires to be easily added.

 

[Crittias]

Originally posted by: Zap
Actually very likely possible, especially on a fan that isn't quite dead. You need to peel back the sticker on the hub of the fan on the side that the wires go in the hub. There should be a rubber plug in the middle. Remove it and drip a few drops of light oil into it. Replace plug, replace sticker (or stick some tape over it) and voila! You've just extended the life of the fan. This will not make the fan perfect nor will it be a permanent solution. However, this fix does work.

If you're planning to keep the system for many more years, then do it right and get a replacement fan. If you think you'll be replacing the system within the year, then don't waste any more money on it and do the oil repair.

Well, the fan cables are soldered into a circuit board, so I'm not going to mess with removing it and replacing it. Instead I've got everything opened up and ready for some light oil treatment. I'll get some while I'm out today and see how that does.

 

[MarcVenice]

No zap, the way the fan had to be placed, and the way the wires ran, I could stick them through the grill holes on top/bottom of the PSU, right into a molex connector if I wanted to. But like I said, that didn't work, the PSU won't run without 'knowing' a fan is plugged in.

 

[Crittias]

I was able to apply the light oil to the fan. It's been 5 days and no noise, so it looks like the temporary fix is working.

Thanks for all the advice!