Hair Dryer RAM fix multiple times

Hi, it's likely to stop working at all one day.

Heat gun better...

https://discussions.apple.com/thread/3916312?tstart=0

That machine has solder fault so what you are doing is to heat up the contacts so they enlarge just enough to make contact. The famous Nvidia defect in Macbook Pro -machines is about the same thing, solder contacts crack and the chip cannot function at all or properly. By using heat gun you might be able to melt and reconnect the joints, I currently write this by using Macbook Pro which I fixed by using that method. However, to create solid connection by using non-professional soldering tools is difficult. I had the heat gun, infrared thermometer and some flux and so far this machine has served me one year after the fix but I expect it to fail again eventually since I cannot replace the bad solder material under the chip, just reflow it.

The problematic chip is on the other side of the motherboard so you will need to remove the motherboard to gain access to it. You cannot perform succesful reflow while the motherboard is inside the machine.

The BGA shown in this link:

http://www.cesgeekbook.com/2010/07/apple-powermac-g5-high-speed-fan-fix.html

The BGA that has the paper "block" on it for pressure is a primary source of trouble.

The other is on the back side of the board and is the RAM slot connections, identifiable by the shape (long, paralel rows of solder).

Not necessarily.

You aren't heating the chips, you are heating the solder of the BGA.

You do want to secure any part/chip that you will attempt reflow, as if upside down and the solder melts, the part/chip may fall off the board.

In this case, though the chip is on the backside with the heatsink on top of it, the BGA is seen to the front side.

Remove everything you need to reveal the chip itself. Surround the chip with aluminium foil, three or four layers, it is not necassary to cover the whole motherboard, just the surroundings of the chip. One thing that you also want to avoid is the flexing of the motherboard so you must support the backside of the chip somehow, if the board flexes too much then you may kiss the G5 goodbye in most cases.

It would be wise to have infrared thermometer which you can use to measure temperatures, the board might work fine for a while after reflowing it "blindly" without knowing the temps, but most likely you will either heat it too much (and cause damage) or too little to actually melt the solder which is the key for a bit longer lasting fix. It is not recommended to heat too quickly as you might cause all sorts of components popping out like popcorn in a microwave (been there done that).

Great to hear! 🙂

So I did the reflow a couple days ago and so far everything is working fine.

Amazing how well things work when they are properly connected! 🙂