mathj said:
but i think if the chip has actually fallen off the board i think its past the heat gun fix
yeah you're probably right, wouldn't stop me trying though
theoretically what works for a couple of dry joints could work for a couple of hundred.
BGA chips and tin/copper solder have a lot to answer for, but isn't something like hikaru old enough to be a lead/tin mix? just might make it easier.
as im somewhat a novice and have more enthusiasm than knowledge (which I know gets on some peoples tits at times) so I read wikipedia, which counts as in-depth research as far as im concerned;
http://en.wikipedia.org/wiki/Rework_(electronics)#Reflowing_and_reballing
so basically you can have the pro-job done (3 month warranty on a notoriously unreliable process even when done on a factory assembly line)
or you can do it DIY, which is basically the same thing but with in less controlled circumstances.
both involve heating the device to the melting point of the solder and both can shorten the life of the device.
having witnessed the care and dedication of certain 'professionals' in various trades i'm reasonably happy to take the careful amateur approach.
refined as far as I can. I did use a method of preheating to lessen thermal shock by using a vac-former oven (sounds like a hatching device for new arcade enthusiasts
) to raise the whole board to ~60c before I heatgunned the affected IC.
one of these;
http://en.wikipedia.org/wiki/Infrared_thermometer could make the amateur process a bit more controlled i guess.
anyway its an interesting thing to learn about, and I consider myself marginally more learned on the matter than Joe Public now. The phrase 'a little knowledge is a dangerous thing' comes to mind.