They are normally soldered on in my experience.

If you open it up, leave it unplugged for a long while! Or you might be in for a shocking experience.

Typically I'll leave it unplugged on the bench for like 3 days before I open it up.

You can take out the old fan and mounting a replacement fan is pretty much straight forward.
The more problematic will be where your new fan will be getting it's power from.
Inside the PSU fans can be connected in basically 2 ways:
Either they are plugged in with a fan header (often larger and not compatible with the normal 2/3 pin fan headers) or they are soldered straight to the PCB inside the PSU.

I replaced a fan like that once. The old fan would not even spin up anymore (and here I was thinking "Damn, this PSU is silent! 😁 ") so I removed it. It had a fan header so I replaced it with a known working fan from another dead PSU. Still no go, apparently the old fan had locked up and somehow destroyed the fan connection.
In the end I just plugged a molex2fanconnector part thingy outside the PSU, let the fanadapter wires to the inside of the PSU along the other wires coming out of the PSU and attached the fan there.

Been using that same PSU as my standard test PSU for about 3 years now 😉
I know the PSU should be ok since I got it from my own uncle, I know the background of that PSU. He had told me the PSU made lots of noice and when I tested it, it was soooo silent! 😜

Ah! That's a good idea. Do most (if not all) PSUs allow you to "rip out" the fan, if it's either soldered in place, or if it uses a fan connector header? What I mean is, do any PSUs say to themselves "hang on a minute, the fan isn't there any more - I'm not going to switch on and provide power, because otherwise I will overheat". If most PSUs don't care if the fan is connected any more, then I would like to try putting in a new fan, and connect it up using the PSU molex connector with an adapter.

retro games 100 wrote:

Ah! That's a good idea. Do most (if not all) PSUs allow you to "rip out" the fan, if it's either soldered in place, or if it uses a fan connector header? What I mean is, do any PSUs say to themselves "hang on a minute, the fan isn't there any more - I'm not going to switch on and provide power, because otherwise I will overheat". If most PSUs don't care if the fan is connected any more, then I would like to try putting in a new fan, and connect it up using the PSU molex connector with an adapter.

Never noticed that. Most are soldered in, unfortunately. I just cut the wires as close to the PCB as I can (so nothing can get shorted). The fans themselves seem to always be mounted with the usual 4 screws.
Gutting PSU's is the best way to obtain those standard fan screws 😁

I've changed many PSU fans and yup most of the time they are soldered in. It's not a big deal. Snip the wires and solder your own fan in and put some heatshrink tubing over the solder points.

Just don't fry yourself on the giant caps in there. We need your retro presence.

Many modern power supplies have temperature regulated fans but on all those PSU's I've opened, the thermal sensor is soldered, so to say, between the powersupply and the fan itself.
So if you remove the whole thermalsensor+fan thingy and solder in a new one, the powersupply won't even 'know' that theres a thermal sensor missing!

All the PSU does is provide power to the sensor+fan combo in much the same way it provides power to your harddrive, dvd or any other thing you connect to it. The only difference is that the sensor+fan assembly is connected from the inside of the PSU instead of the outside.

Soldering a new one (which I don't do as I suck at soldering 😜 ) won't make your PSU not turn on, to the best of my knowledge 😉

Many thanks for the info people! 😀

some things to add:

The fan of a PSU has to

- cool the PSU
- get the hot air out of the case

So if the dimension - or cfm value - of the fan is to small

- the PSU will get very hot
- and the case and all the components inside also.

From the link you posted the PSU seems to be a two fan solution.
This solution is not very common any more - most manufacturers produce PSUs with one big fan (10, 12 or even 14").
That's not only because it's cheaper but I think also because it's safer.

In a two fan PSU the cfm value of the '"inward" (in your case "A") fan should not be bigger than that of the "outer" (B) fan. If it is, it blows more hot air into the PSU than B can blow out.

So carefully choose the fans you want the original ones to replace with.