Use the tweezers to remove the zebra connector that is between the daughterboard and the motherboard.

Carefully clean it with 95% isopropyl.

In my picture, you see the black contacts on the motherboard. These have to be very carefully cleaned. Electronics cleaner did not work. Note that the contacts are plated with gold. Unfortunately, this corrosion got between the gold and the copper and now the gold is gone.

I cleaned the contacts by rubbing the flat side of the tips on the contacts until they were, not shiny, but clean. This is bare copper and now is even more susceptible to corrosion. :(

Do not store your device with batteries in it. You run the risk of pulling the copper pad off the pc board. If this happens, you’re screwed. It is still possible to fix your device, but the process is beyond the scope of this document, requires more tools and a very steady hand. I hope you had the good fortune I had