G3 B&W ATX-Fan Power?

3 replies [Last post]
Joined: Dec 19 2003
Posts: 26

I've recently swapped out my original noisy as hell and huge as a house stock G3 B&W power supply for a cheap 300w Micro ATX PSU. Snipped the 5v wire and it works great and is ideal size wise for the hack its currently 'living in'.

However, I hadn't done any homework on how the (stock) fan was going to be powered.

Let me say this now, I don't know anything about electrics/electronics! If someone can tell me how to do anything in this respect, I'm perfectly happy to carry out the required steps!

So, my question is this:

I have several connectors that I don't need on the PSU, namely one for a Pentium 4 (I think) and a Floppy Disc drive.

Now, The stock G3 fan has two wires, one black and one red, and these are connected to the PSU via some kind of connector, which has two wires, one yellow and one black.

How can I connect a fan? Am I able to connect it to the floppy or P4 wires, or will there be more power going through those than needed for a fan?

My ideal would be this: to mount a fan on the CPU.

Would someone be able to guide me to the type of fan I need? (I live in the UK if that makes any difference?).

I've looked at fans before and I find it all a bit mindboggling.

BTW-The CPU at present is cooled by the fan from the PSU, BUT-this is just a temporary measure, it can't live there as its supposed to be at the 'back' of the case. One reason being so I can disconnect the kettle lead when needs be!



MBP 2ghz, G4 1gig MDD, G4 15" 1.33 PB, Col Classic Takkoid G4 500mhz 10.4" LCD (w.i.p), 5500/G3

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eeun's picture
Joined: Dec 19 2003
Posts: 1891
The fan's red wire can connec

The fan's red wire can connect to one of the power supply's yellow (usually) 12V lines. Black connects to black ground wire. Any free connector will do, and the fan won't draw any more power than it needs.

If you don't want to get into cutting connectors and splicing, you can buy a 120mm PC fan that comes with a 4-pin molex. Installation is then plug and play.

Most of These on ebay.uk come with the 4-pin molex connector. And blue LEDs suit the B&W G3 nicely. Wink


"Give a man a fire, he's warm for a day. Set a man on fire and he's warm for the rest of his life."
(Terry Pratchett)

Joined: Dec 19 2003
Posts: 26
great stuff

thanks for that. I didn't realise you could get fans with molex connectors, obviously makes life a lot easier Smile

I ended up getting a 50mm Akasa fan with a 3 pin connector (so i could drill and screw onto the G3's Heatsink) and then I bought a 3 pin to molex adapter, so it should all work out fingers crossed.

I would've cut the wires, I wasn't scared of doing that! Just had to know which one etc.



MBP 2ghz, G4 1gig MDD, G4 15" 1.33 PB, Col Classic Takkoid G4 500mhz 10.4" LCD (w.i.p), 5500/G3

Hokusai's picture
Joined: Dec 20 2003
Posts: 256

I've always noticed on B&W motherboards that there is a spot near the processor with '12V Fan' written next to 4 solder points for a fan connector. I've always wondered if you could put a working connector on there.


Macbook Pro 2.5GHz i5 / 16GB / SSD / eGPU GTX 960
Powerbase 360MHz G3 / 160MB / 80GB ATA / Radeon 7200