Amiga 500+ leaking battery and other issues/questions

[paul1981]

I'd suggest pulling the socketed chips which appear to be affected with the green corrosion and cleaning the chip pins and socket. If you had green on the pins then there will be green in the socket contact, hence it is not working. I'd say that's the likely reason from looking at your photos.
Socketed chips can require reseating anyway over time, even without corrosion. Same with wire looms/plugs and such.

[paul1981]

Regarding Gary, it might be worth while dipping all the pins in a vinegar bath for a minute (or use a cotton bud to apply) and then rinse off with water.
The pins can be carefully sanded with a very fine grain sand paper if contact cleaner or WD-40 doesn't bring them up. I suppose in a nutshell you've go to try and make them look pretty decent, like they're electrically conducting pins.