Hello, I have a couple repair questions for 128k/512k machines.

1) I have 2 of these machines that show no video unless the analog board is flexed, then BAM is pops on and looks great. I assume this a solder joint issue? Any joints likely to fail so I don't have to go through them all?

2) Where is a good place to buy replacement batteries? eBay has them, but they are $12+ a piece with shipping.