BGA Reworking: Reball & Reflow
Reflowing is a process where we heat up the original chip that fails on the board due to cold solder joints underneath the chip.
This is caused by heat, flexing and poor design. Reworking the chip can causes the weakened and cracked solder to form a better joint.
However the main problem is still there! All Manufacturers have to use lead free solder, which is required by USA/ EU law that any any electronic must use lead free solder. This is where the poor design comes into play.
Reballing is a process where we lift off the defective BGA chip and A) Repair it by put lead based solder (stronger solder) on the chip and placing it back on the board or B) Replacing the chip with a new / refurb replacement as well as using lead based solder on it and placing it back on the board.
Why does this work 99.5% of the time? Because the 99.5% of the time the main problem is either bad BGA chip or bad solder.
So what is the 0.5% cover? The actual BGA pads on the board that connect the chip to the board are bad or degraded. This is rare and if this happens it can be repaired, but is very time consuming and expensive. The cheaper option will be to replace the mainboard.
Why is reworking better then sending it to HP, Dell, Microsoft & Sony etc;? HP, Dell, Microsoft & Sony etc; will use lead free solder which is very brittle and can break easy, which is the reason your device failed originally.
I am sure you know of some people that have had their Xbox 360 or Sony PS3 replaced multiple times for the same exact issues. Now you know the reason why and you can tell them.
Why does my Wii or old laptop never fail? Because they do not use overpowered chips on there system causing a lot of heat, causing damage to the board or chip!
Why does Sony and Microsoft do this then? Because the consumer demands high end graphics!