[mikerally]

Hi guys,

I thought I'd post in here before I think about consulting Apple about it.

I own an original 12 inch Powerbook G4 (Revision A) which I've had for about two years now (since the first week of February 2003, so it's pretty much one of the first ones to roll off the manufacturing line).

And apart from the rubber feet falling off a couple of times, I've had no problems with the laptop at all (despite what everyone on here says about revision A models) - that is until now.

Just so you know, I did not buy extended AppleCare, so this computer is no longer under warranty.

I use this laptop a lot, it has easily run over a couple of thousand of hours use (I've use the thing to encode stuff and download a LOT). And it's pretty much starting to show it's age because one of the onboard fans is showing some very early warning signs of failing (I think the bearing is starting to go or something).

The machine runs fine itself, it doesn't crash, or hang or anything like that and the CPU temp doesn't rise dramatically (monitoring using some CPU temp monitoring utility).

The fan seems to operate normally at low RPM speeds, but whenever it is kicked into full speed (when I'm doing something heavy duty) it starts to make some sort of grinding noise (a very scary noise to hear from you Powerbook for the first time!!!) - over the time this starts to escalate until I think the fan actually ceases up - at which point the Powerbook senses this and cuts the fan and restarts it (at a low speed).

This has only started in the last couple of days.

Now I've got a couple of questions:-

- Can anyone suggest a piece of software that allows me to monitor the RPM of my fan (and allows me to check how many fans there are and which one is failing)? I've check VersionTracker already and found a program called "Hardware Monitor" and another called "Temperature Monitor" (essentially the same program infact) - but they don't report the fan RPM on my Powerbook.

- How many fans are there in my Rev A Powerbook? How much are the spare parts typically (I will be checking pbparts.com later) - does anyone know how easy it is to replace them, or would I have to replace the entire heatsink/fan assembly?

Just so you know, I'm already trying to find the answers to get this resolved, I'm very capable at replacing parts myself, I've disassembled tray loading and slot loading iMacs before. I'm already looking for one of those Apple Service Technician manuals in PDF format for my Powerbook (I will get it off BitTorrent).

I would apprieciate any comments or suggestions.

I am considering getting a new Powerbook (mine is quite slow and old anyway), but I'm holding out for the Powerbook G5.

[mikerally]

Right, it's great to see that nobody seems interested in saying anything.

I found out a couple of answers for myself :-

- The Rev A and B models only have one fan (I don't know about later models, but I assume they are the same as B), it's placed right at the back where the speakers/hinges are. On the Rev A model it's part of Heatsink and Fan Assembly, on the B models and later it's an individual part (but in the same location).

- As the grinding noise only ever comes when the fan spins up hard, and there's only one fan, I'm guessing that it can only be the fan at fault.

- I can order a replacement Rev A Heatsink and Fan Assembly for �52 (about $100) from VIS here in the UK.

- I opened my Powerbook up using the Service Technician Manual I downloaded and had a look/poke around at the fan - it looks fine (it's not clogged with dust, and nothing is caught up in it). I stopped short of attempting to remove the entire heatsink/fan assembly (to look at it), it's a pretty complicated procedure.


I've reassembled the Powerbook and it's working ok, but the fan is still making the noises (not as bad as before, but it's still there). The machine otherwise works fine.

I have some tough decsisions to make, I don't feel like I'm ready to sell this Powerbook on yet and move on to another.

I guess my next move is to go down to the Apple Store and get a quote on how much they would charge to replace the part. If it costs too much I'm going to look more seriously into replacing the part myself (I'm a very capable person).


I really would like some feedback/suggestions on this issue.

[bbales]

Hi -- I have the same laptop and it caught my attention. I will not be any help to you, I'm afraid. I jsut have a question. You mention a grinding noise -- are you sure it's the fan and not the hard drive? I've never done this myself but you could run the hardware test that comes on the install CDs. (That could check the hard drive as well. Good luck -- and let us know what happens.

By the way, I've had great luck with my Rev. A machine, too -- screen needed to be replaced 13 months after purchase, but I DO have AppleCare, so that was OK. And my rubber feet are an issue...

[polendo]

I think that jet propulsion noise is normal when the fan kicks in high gear. I was also really scared when I heard that noise for the first time (in a 12" iBook)
Nevertheless, could it be possible that when you heard the noise was the first time it got the fan in high speed? I heard that noise for the first time when about 6 month after I bought it. It was in the summer and was kind of hot at "room temperature".

[Dr.Michael]

Originally posted by mikerally:
Right, it's great to see that nobody seems interested in saying anything.

I found out a couple of answers for myself :-

Well, since you have looked up the easy to find info (and thus made your homework now), you get your answers ;o).

Fans don't live forever. In the 12 inch powerbooks they spin up a lot and since you write you use your powerbook a lot, the fan is likely worn out. Normal operation time is 6 months nonstop at full speed for high quality fans.

I would look at the case of the fan and try to find evidence that the fan scratches its case somewhere. This can be a sign of worn out bearings but you can easily manipulate the case to stop the noise.

What can also help for a limited time is thick grease applied to the bearing of the fan (you have to disassemble completely). Disassembly is quite an effort. In your place I would buy a new fan and replace the unit. But save the money for the heatsink. You don't have to buy it.

But: If you remove the heatsink you will have to buy new heat conducting pads for the cpu and gpu (the white stickers that can be seen on top the two chips in disassembly guides) . Once they have been removed the heat conduction to the heatsink will be less efficient. So they have to be replaced. Look in electronic stores and buy the ones with the best heat conduction you can get.