G4 ibook motherboard fault.
There is a problem with the logic board in the Macintosh G4 ibooks. It can appear after a year or more in some machines and the symptom is that after being on for a few minutes, the screen goes black (it looks blank, but the light has gone off) , the fan turns on, and the computer freezes. You might think it is a problem with the display but it’s actually a problem with one of the chips on the main motherboard. This article describes the problem and how to repair it.
What models are affected?
I conducted a survey (thanks to over 300 readers who participated!) to see which model g4 ibook had the problem. The results are here and it appears that every iBook model can develop the blank display problem.
Thankfully the Aluminium power books don’t have the problem. In fact the powerbooks from this era are a great design, the 15 inch Aluminium G4 powerbook is one of my all time favourite macs – I still have one.
The original 2003 ibook G4’s (800/933/1Ghz) have the fault.
The “Early 2004″ (1Ghz) models up until Oct 2004 have the same motherboard.
The 60G (1.2Ghz) “Early 2004″ model and all the “Late 2004″ model ibooks (1.2Ghz/1.33Ghz) and Mid 2005 (1.33 and 1.42Ghz) have different logic board (built in airport extreme)- but they still have the fault – even models with the new logic boards are affected!
What is the fault?
One of the chips heats up and cools down each time the computer is turned on and off, so that eventually a small stress crack appears on one of the pins. When the computer heats up and parts expand, the crack opens up and the power does not get through. This means the display goes blank and the computer freezes. If you press the plastic case of the ibook in just the right place, it can put enough pressure on the chip so that the pin makes contact and the computer will power up again. In fact, here’s a crude DIY repair method involving a shim where you open the laptop and put a piece of rubber on top of the chip to press it down: http://coreyarnold.org/ibook/?p=20
Here is another DIY solution is that involves clamping a g-clamp onto your iBook – I would not recommend this one it will place all sorts of physical stresses on the iBook internals!
Here is a photo of the fault developing. (from here: ENGF959-orig). You can see the thin black line running below the lead which is a crack in the solder.
You need a fine tipped soldering iron to heat up the top few pins of the chip one by one and resolder them to the logic board. Press the chip down while you apply a very clean and fine soldering iron tip to each pin.
Don’t attempt this one unless you have had some soldering experience – or you are ready to say goodbye to your G4 ibook if something goes wrong!
Here are some pictures:
The G4 ibook with the bottom case off. The offending chip is circled.
Here is a closeup of where I have soldered the legs of the chip. You can see the base of the top pins are shinier and a little fatter from the new soldering. I soldered the top 3 or 4 pins on each side, but it’s only the top 2 pins that the fault occurs with as they are the main power pins. I applied a little more solder to the joint as well, that’s why it looks a bit lumpy.
TYou don’t need to apply any new solder to the chip. Just apple some solder to your soldering iron to clean it. Then wipe the iron clean on a rag. Then gently touch the iron to the legs of the chip for about 3 seconds each leg to melt the solder down onto the joints again.
Here is a close-up of the chip you are soldering. Solder the end with the little circle on it. Solder the top 2 legs on each side.
STOPPING THE FAULT FRM OCCURRING
As pointed out in the discussions below, once your ibook is fixed, or if your G4 iBook has not yet developed the fault, you might want to take out $10 worth of insurance by buying this little app.
It turns your fans on earlier and lowers the internal temp of you ibook. You can set the temperature lower so that your fan turns on a little sooner to keep the iBook cooler.
If you repair your iBook be sure go make a post below. So far there have been lots of successes and no failures at all!