Power Mac G4 Quicksilver main case fan replacement

mac27 said:

Just documenting a quick little repair/maintenance item I took care of today. The main case fan in my Quicksilver was nice and quiet, but it had developed a really annoying rattle with age. I found a suitable replacement on Amazon that has the right dimensions (120mm x 120mm x 25mm).

The original fan only had two wires with a dual-pin connector, so I had to chop that off and solder it onto the new fan's cabling. The new fan had a three-wire harness but the third wire is just a signal cable that these old machines don't use.

The new one fit right in and works well. It is a bit louder than the old one (kinda sounds like an MDD now), so if anyone has recommendations for a different model that's quieter I'd be up for swapping it out again in the future. But other than that, it was a pretty painless job.

View attachment 25932 View attachment 25933

New fan (left) and orignal fan (right) that had two-pin connector which has to be cut off and soldered onto the new harness.

View attachment 25934

Installed back into the QS case.

Click to expand...

Aftermarket fans are really hit or miss with noise. Noctua is always a solid choice if you don't mind the odd color scheme, and they often include an adapter to lower the RPM. The OEM fan has a built in thermistor to vary the RPM and that helps a good bit with noise.

Here's two of the OEM fans new on eBay: https://www.ebay.com/itm/1415944119...OUb7IkUWjhvkH/5q3PLLlDRg==|tkp:Bk9SR_j8l_D1Zg

mac27 said:

Thanks, I'd assumed NOS OEM parts wouldn't be available, but nope. I picked up one of these lots and will try that out instead.

Click to expand...

FYI, for anyone having trouble finding a properly spec'd replacement fan (I am a fan of Noctua personally), PTFE lubricants like 3in1 and Triflow have workd really well for me on aged existing case fan bearings. Every couple of years or as they get loud, a few drops on the bearing assembly quiets everything down - especially useful on the QS's cranky cpu heat sink fan that is sandwiched between the heatsink and the back. Of the two, 3in1 is pretty easy to find - most hardware stores carry it and works great but my preference is tri-flow as it is a whee bit thinner and has this very handy transparent extendable application tube which is great for seeing the incoming lubricant travel down the tube so you dont make a mess and over-lubricate.

Subsequently, I use the tri-flow not only on loud bearings but on hinges and joints of all sorts, is a mircale for sticky door locks as well as my bikes & my kids bikes for seasonal maintenance. Works great there too. It is a very handy lube to have around.

I love the Noctua NF-A6x25 FLX for my SE/30 and thought about replacing the Quicksilver internal fan with it, but the existing fan isn't really a sound issue like it is when the compact mac is sitting in front of you.

I still might replace the big' ole fan if it proves to be loud though. I have yet to boot the thing into OS.