08/27/2016, 08:35 AM
I contacted the Chinese seller I got my 2GB chips from, and they insist these chips are genuine, and not defective or fake. They say they sold over 5000 of these recently and no one has had any problems. Hey, I had to ask, right, for whatever it's worth?
It's just as likely that I've been using too much heat, and damaged the chips. I didn't really consider this previously, but the more I am researching, using 380C hot air may have been too much.
So I will try again later today with the heat dialled down to 300C, or less. The problem is you have to transmit enough heat through the top of the chip to melt the solder balls on the bottom. The lead-free solder melts at 250C, and that's about all these chips can stand. If you set the heat to 250C, it takes a long time for that heat to get transmitted through the chip to the underside, maybe even never. Maybe I'll experiment a bit more with one of the "used" chips.