PowerBook G4 A1138 Cooling Fans

The left fan in my 15" PowerBook G4 A1138 has been making rattle/buzzing noises when going over 1400 rpm. I cleaned the dust from the fan and vent, and I thought the noise went away, but it has returned. At low speeds, the fan doesn't make any noise, so I don't think it's a lubrication problem - but I'm not sure.

I've researched the option of replacing the fan, but there is some confusion as to what is and is not a compatible part. Many websites say the proper fan should have a part number of 922-7100. This part number seems to be unique to the A1138 model, as all other Aluminum PBs used part number 922-6232.

Powerbookmedic lists a PB 15" left fan as having both part numbers, which leads to the assumption that the fans are interchangeable (yet their model compatibility list does not include the A1138). Some other websites selling fans give the same information.

However, most websites make a point of saying that the 922-6232 fan is specifically not compatible with the A1138, despite their similarities in appearance.

Does anybody have any experience or knowledge about the 922-6232 fan working in the A1138? What is the difference between this fan and the 922-7100? Thanks.

Call the folks at Powerbookmedic.com and ask. I believe they still have an 800 number for tech support. Here it is: 1-866-726-3342

The fan bearing is probably dry. You may be able to carefully put some lubricant back into it. Sewing machine oil works well if you use a small eye dropper. Just make sure no oil gets on the board. You may have to completely remove the fan first - which is probably the best way to do it.

chscag said:

The fan bearing is probably dry. You may be able to carefully put some lubricant back into it. Sewing machine oil works well if you use a small eye dropper. Just make sure no oil gets on the board. You may have to completely remove the fan first - which is probably the best way to do it.

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I've never oiled a fan before, and I'm not sure what kind of bearing it has, but I'll give it a shot anyway. I guess I'm supposed to peel back the sticker and a little stopper thing, then fill it with oil? Thanks!

I've never oiled a fan before, and I'm not sure what kind of bearing it has, but I'll give it a shot anyway. I guess I'm supposed to peel back the sticker and a little stopper thing, then fill it with oil?

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Yes, but be careful not to use too much. A couple of drops of light oil should work well enough. If you use too much, it'll leak out over the board and can possibly cause problems.

Well, that didn't work out as planned. Where I thought I would see a rubber or silicone stopper, I saw a metal cap. I thought that maybe this was just the top of a stopper, so I tried to pry it off. That didn't work, and I ended up breaking off the edges of the cap (if that's even what it is) all the way around in the shape of what is now a broken and twisted ring. The fan blades easily come up off the motor, so I'll just try adding a little oil to that shaft to see what happens. Oh well.