On 30 Oct 2007 15:48:35 GMT Jim Yanik wrote in Message
id: :

[...]

it seems that the only reliable way would be to remove the BGA chip and
somehow put new solder balls and flux on all the PCB pads,then reinstall
the BGA and reflow using a preheat hot plate and hot air gun.
Never tried it,though.

I don't think I'd attempt it but:
http://www.finetech.de/enid/Rework__...ents _fo.html
I doubt it'd be economically feasible for the devices we use. When we have
a BGA that has failed solder joints and it can't be fixed with the Hako,
we send it out to have the chip replaced.