Originally Posted by AdamOutler
... It takes a multi-thousand dollar professional setup in order to make sure no damage is done. I use a digital temperature controlled heat gun. It works, but it's not accurate.
Sorry Adam, you have a great writeup, but this is really a BS statement!
-- You can easily unsolder a BGA chip with a $5 micro-blow-torch! You just have to make sure you shield the surrounding components from the excessive heat. Put a small piece of copper (a penny?) on top of the chip, then put a piece of low-temperature (lead-free) solder on top of the coin, so you can get an idea when you have enough heat. Continue 10-20 seconds. Very carefully try to jam a few sharp toothpicks under any space between chip and PCB. Never bend!
This technique is well known and well demonstrated on YouTube, ever since the HP/Nvidia scandal of video chips falling of the MOBO after dust blocking the fan intake with (purposely) under-dimensioned and faulty heat-sink design.
The problem is getting it back ON! Then you need to invest in a professional heat plate and re-balling grid.