@AAMorgan @Mac Hosehead and @FMEng Read and head @FMEng 's comments in post #2 before disconnecting, cleaning and replacing your previous Varta battery.I would try to clean the board up as much as you can. I first replaced it with a battery from ebay. It didn't last long but you could know if the console is going to work.
Toodleoo!
Ron Hebbard [Proud restorer and reviver of three derelict, abandoned and still surviving Strand 300's.]