You really have to take the PSUs apart, clean them well enough and possibly replace the fans for a long term solution.

devius wrote on 2024-07-09, 21:06:

You really have to take the PSUs apart, clean them well enough and possibly replace the fans for a long term solution.

I was afraid of that. How hard is it to get into a PS on one of these? I took apart my 5150's power supply once and it was a pain in the a**

Some are easier then others but PSU's are all built pretty much the same. Not hard to open but can put up a fight. At least nothing is breakable unlike faceplates on a case.
Just take your time and after the first time you'll know the "secret" on how to open.

chinny22 wrote on 2024-07-10, 00:21:

Some are easier then others but PSU's are all built pretty much the same. Not hard to open but can put up a fight. At least nothing is breakable unlike faceplates on a case.
Just take your time and after the first time you'll know the "secret" on how to open.

I think the biggest problem will be getting it out of the case without damaging anything.

I have a ValuePoint 450DX2 but haven't done any work to it yet, so no idea how easy it is to get into the PSUs of those, but I did service a PS/2 Model 30-286 and taking the PSU out of the case was not hard, but I didn't open it because the plates aren't screwed together, they're riveted. Thanks IBM! I did shake it a bit and cleaned with a small brush through the orifices as best as I could, but that one was already pretty quiet.

I also had a IBM PC300GL Pentium 200MMX at some point and I believe that one wasn't riveted.

Once open ideally you want to replace the fan and a capacitor check while in there. Make sure none are bulged. The fan might be connected to the PSU board with a 2 pin connector (lucky if that's the case) , or just soldered. I just clip the wires on the upper end and solder together with the ones from the new fan. Make sure wires are insulated properly and that's about it. Replaced a few like this and never had an issue.

devius wrote on 2024-07-10, 21:20:

I have a ValuePoint 450DX2 but haven't done any work to it yet, so no idea how easy it is to get into the PSUs of those, but I did service a PS/2 Model 30-286 and taking the PSU out of the case was not hard, but I didn't open it because the plates aren't screwed together, they're riveted. Thanks IBM! I did shake it a bit and cleaned with a small brush through the orifices as best as I could, but that one was already pretty quiet.

I also had a IBM PC300GL Pentium 200MMX at some point and I believe that one wasn't riveted.

I have a really little little brush that I can try using to clean things out. Maybe I can get a little lube on the shaft (ok that sounded way dirtier than I meant). The fans aren't mega loud, but they could probably use a good cleaning anyway. I think the builk of my noise is coming from the hard drives.

Depending on the fan type, you might be able to lube the fans or you might have to replace them completely.

If it's a sleeve bearing fan, chances are it can be opened and lubricated. Usually, this can be done by removing the sticker on the back of the fan, which should give you either access directly to the fan shaft or to a rubber plug that then reveals the shaft. Most people just put some oil in there and call it good. However, if you want longer-lasting results, then there should be a c-clip on the shaft that you should be able to remove, which will then allow you to take the rotor assembly off and give you access to the sleeve to clean it with IPA. For lubricant, use machine type oil. Other oils (standard engine oil or ATF) are OK too. Just avoid grease. And remember: WD-40 is *not* a lubricant.

Now, if it's a ball-bearing fan, chances are the ball bearings are bad (or, there's a small chance the fan is just noisy because it's always been that way, as some old fans were always noisy to begin with.) You can either take the long road and look for replacement bearings (often the cost of these will surpass the cost of the fan, if you can even find them for sale individually) or just replace the entire fan. But if you replace the entire fan, you need to make sure the new one will have similar performance spec so that the PSU still cools the same as before. --OR-- if you want the highest challenge, then you can try to take apart the ball bearings and repack them with white lithium grease (but it's fiddly work, so I don't recommend it.)

Either way, take your time and have fun with it. Shouldn't be that challenging to get to the fan (though I don't have any particular experience with this exact same machine, so I may be wrong.)

Any idea how to remove this fan from the case so I can get into it?

The fan is inside the PSU. You need to remove the PSU from the case and open it, as devius already told you earlier and you acknowledged. If you are not comfortable doing this maybe find someone who is and do it together?

Usually PSUs are mounted with 4 screws at the back of the computer so probably you need to remove the plastic shielding of the back of the computer first. Probably held with plastic tabs, be careful not to break these. Then to get into the PSU there is commonly a couple of screws and then you need to pry the metal plates apart as they are usually interlocked.

Check if there is some YouTube clip of someone disassembling the specific computer if you are unsure how to.

Oh and be very careful with the big caps as they can hold a dangerous charge.

konc wrote on 2024-07-16, 07:42:

The fan is inside the PSU. You need to remove the PSU from the case and open it, as devius already told you earlier and you acknowledged. If you are not comfortable doing this maybe find someone who is and do it together?

Yes I know that, I meant how do I get the PSU out of the case so I can open it. Sorry if I wasn't clear.

Joakim wrote on 2024-07-16, 07:45:

Usually PSUs are mounted with 4 screws at the back of the computer so probably you need to remove the plastic shielding of the back of the computer first. Probably held with plastic tabs, be careful not to break these. Then to get into the PSU there is commonly a couple of screws and then you need to pry the metal plates apart as they are usually interlocked.

Ah thank you. I'll be ok, I poke around the backs of large CRTs all the time. I know what not to touch. 😀

So, your first step should have been to unplug all external cables. Then, all internal cables that are connected to the PSU. If you want to be thorough you should also remove *all* internal cables so you can more easily clean the insides. Then, remove the plastic plate as Joakim mentioned, then look for all the screws that are keeping the PSU in place and unscrew them. From the looks of it you'll have to remove all the front drives and/or their cage to be able to access some of the screws. This is par for the course when it comes to brand computers.

Just wanted to share a funny thing that occured to me this morning on the subject of fan noise.
I had a small noisy 486 CPU fan that I wanted to fix. So I opened it and gave it a clean and machine oil, then turned it on before putting it back. It was quiet.

However, after I installed it on the CPU the annoying noise came back again.

Started to touch the fan and the heat sink and noticed the noise goes away even by touching the heat sink... then by just touching the motherboard itself!

Apparently, the fan itself was quiet from the get go, but it was causing vibrations that went across the mobo and found a slightly loose part of the mobo that rattled against the case! It was just a matter of padding the case at that location to kill the noise.

Just mentioning this here in case it turns out your PSU's fan was causing such vibrations.

Good luck 🙂

Actually as it turns out it was mostly the hard drive. Once I replaced it with a CF card the noise went down to an acceptable level.