Update 9/26/2008: Two years and both of my ibooks are still running.
I have two Apple 12″ iBook G4 laptops (800MHz and 1064MHz). One belongs to my roommate and the other belongs to me. My roommate’s died about 9 months ago and mine died about 1 month ago. Both laptops failed with the same symptoms: a black screen and a loud, whirring fan on bootup. If this is not the problem your machine is having this fix mayNOT work for you. After doing some reading I found much information on the Apple iBook G3 logic board failure. Apple has instituted a replacement program for the G3s and there are also some hacks available for fixing it yourself. On the G3s it seems the problem is that the GPU becomes partially detached from the logic board. On the G4s it has been speculated that the problem is the same, but this does not seem to be what I have found. Initially, as suggested on some websites, I tried shimming my G4’s GPU by placing some copper strips between the heatsink and the GPU, but the machine still would not boot.
A popular fix that does work is to use a c-clamp to clamp the iBook G4 to a table, in effect squeezing the logic board. Obviously this limits the mobility of the machine and therefore I wanted to try something else. After my many hours of shimming attempts I was left with a still broken computer and a cracked logic board. I began to wonder why the optimal position of the c-clamps do not seem to be above the GPU, making me question if the problem on my G4s is the GPU at all. In a fit of frustration I disassembled my roommate’s ibook and plugged it in. I pressed down on different chips trying to find one that fixed the problem. Some sparks flew, but I found one!
Below are simple instructions of how I shimmed the chip. If you can see broken contacts between the chip and the board, and have the tools and skill, you may choose to solder it as several people have discussed doing in the posts below.
1. Remove your iBook’s lower heat shield by following ifixit’s outstanding instructions.
2. You should now be looking at the bottom side of the logic board. Here’s a pic of my two ibooks with the problem chip outlined and blown up.
3. Now you will need to place a shim between the chip and the heat shield/case. Here’s the little sticky rubber feet I used and what I’d recommend. I also used a rolled up piece of copper on one iBook, but that was just what I had laying around during my aforementioned fit of frustration. Really, anything seems to work.
The shim must be tall enough to reach the plastic case otherwise not enough pressure will be put upon the chip. It seems that the more pressure, the better. However, be very careful not to damage your logic board by using too large a shim! I suggest trying the smallest shim possible and seeing if it works. If you have problems, increase the size of the shim slightly and try again. Keep going until you find the best fit. If you do find your initial shim is too small, you may find it easier to place additional shims between the head shield and the case. You should be able to see the original shim poking up under the shield, just place additional shims on top of it, making sure that the pressure is evenly distributed.
4. Here are pics from both my fixes. One with a piece of rolled up copper (from a cosmetics tube) and the other with a rubber foot. You may have to re-route the power cable around/over your shim a bit. Whatever you do, make sure your shim will place even pressure on the chip when the case is re-assembled. I decided to leave the copper shim in place (instead of replacing it with a rubber one) just to see if it works better than the rubber one.
5. Re-assemble your iBook. Others have found that the hard drive cable may become disconnected, resulting in a flashing question mark icon at startup, so make sure that the orange hard drive cable is still connected to the logic board and the hard drive. The case may be slightly deformed as the shim should be pushing against it. Try not to use a shim that is too large, though, as it may put too much pressure on the logic board causing further problems.
6. Voila!
My two iBooks have been running fine for5 7 days nearly two weeks a long time now.
A popular fix that does work is to use a c-clamp to clamp the iBook G4 to a table, in effect squeezing the logic board. Obviously this limits the mobility of the machine and therefore I wanted to try something else. After my many hours of shimming attempts I was left with a still broken computer and a cracked logic board. I began to wonder why the optimal position of the c-clamps do not seem to be above the GPU, making me question if the problem on my G4s is the GPU at all. In a fit of frustration I disassembled my roommate’s ibook and plugged it in. I pressed down on different chips trying to find one that fixed the problem. Some sparks flew, but I found one!
Below are simple instructions of how I shimmed the chip. If you can see broken contacts between the chip and the board, and have the tools and skill, you may choose to solder it as several people have discussed doing in the posts below.
Please note: while this fix has worked for me on two different iBook G4s I take no responsibility for it working on your machine. Also, you must know that by opening up your iBook you void any warranty you may have on it and chance causing even more damage. That said, let’s have some fun!
Instructions:1. Remove your iBook’s lower heat shield by following ifixit’s outstanding instructions.
2. You should now be looking at the bottom side of the logic board. Here’s a pic of my two ibooks with the problem chip outlined and blown up.
3. Now you will need to place a shim between the chip and the heat shield/case. Here’s the little sticky rubber feet I used and what I’d recommend. I also used a rolled up piece of copper on one iBook, but that was just what I had laying around during my aforementioned fit of frustration. Really, anything seems to work.
The shim must be tall enough to reach the plastic case otherwise not enough pressure will be put upon the chip. It seems that the more pressure, the better. However, be very careful not to damage your logic board by using too large a shim! I suggest trying the smallest shim possible and seeing if it works. If you have problems, increase the size of the shim slightly and try again. Keep going until you find the best fit. If you do find your initial shim is too small, you may find it easier to place additional shims between the head shield and the case. You should be able to see the original shim poking up under the shield, just place additional shims on top of it, making sure that the pressure is evenly distributed.
4. Here are pics from both my fixes. One with a piece of rolled up copper (from a cosmetics tube) and the other with a rubber foot. You may have to re-route the power cable around/over your shim a bit. Whatever you do, make sure your shim will place even pressure on the chip when the case is re-assembled. I decided to leave the copper shim in place (instead of replacing it with a rubber one) just to see if it works better than the rubber one.
5. Re-assemble your iBook. Others have found that the hard drive cable may become disconnected, resulting in a flashing question mark icon at startup, so make sure that the orange hard drive cable is still connected to the logic board and the hard drive. The case may be slightly deformed as the shim should be pushing against it. Try not to use a shim that is too large, though, as it may put too much pressure on the logic board causing further problems.
6. Voila!
My two iBooks have been running fine for
