The Power Macintosh 6500/250 I picked up a while back on eBay seemed to work okay except it made a horribly loud grinding noise. I was sure it must be a bad power supply fan. But when I tried the logic board in a different 6400 chassis the sound went with the logic board, it seemed crazy but the crazy loud noise was from the little CPU fan! I tried cutting the fan sticker label and applying some new lubrication, which did help a little bit but on closer inspection I could see the fan blade unit was wobbling in its mount.
Found some seemingly compatible 12v fans on Amazon and picked this one:
Brushless DC Cooling Fan 12V 0.06~0.15A 40x40x10mm Speed 6800 RPM
Old fan on the left, new on the right:
One issue I found was the new fan had deeper counter sink screw holes that hold it to the heat sink than the original, I ended up using some modified plumbing o-rings to pad it out:
The new fan's power connector wouldn't work with the logic board but instead of splicing in the connector from the old fan I used a new one. Turns out its the same one the LC series uses for the case fan which I had bought a bunch of (2695 connector, two position) a few years ago:
Here's the shortened power wires for the new fan with the terminals crimped (via small needle nose pilers) and soldered on:
And inserted in the plastic connector and installed:
Crazy noise gone! Hopefully helpful info for someone in the future
Found some seemingly compatible 12v fans on Amazon and picked this one:
Brushless DC Cooling Fan 12V 0.06~0.15A 40x40x10mm Speed 6800 RPM
Old fan on the left, new on the right:
One issue I found was the new fan had deeper counter sink screw holes that hold it to the heat sink than the original, I ended up using some modified plumbing o-rings to pad it out:
The new fan's power connector wouldn't work with the logic board but instead of splicing in the connector from the old fan I used a new one. Turns out its the same one the LC series uses for the case fan which I had bought a bunch of (2695 connector, two position) a few years ago:
Here's the shortened power wires for the new fan with the terminals crimped (via small needle nose pilers) and soldered on:
And inserted in the plastic connector and installed:
Crazy noise gone! Hopefully helpful info for someone in the future
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