Hi, I've recently got my Dads old 256TC and am in the process of trying to get it running. My dad used to run a microbee store in Queensland in the 80s and I spent a lot of time playing games on it as a young kid.
Excellent stuff!
Open it up and hope the battery backup battery hasn't leaked.
The alkaline eats up the fine PCB traces & can get into the keyboard connectors and flexible cable.
Yes , always thought that was a silly idea as almost at the same time I was repairing XT clone plug in clock daughter boards with leaking batteries. In fact on one of my workbenches now is sitting a MIDI controller a fellow musician mate has asked me to repair , someone had left the batteries in , they went flat and leaked all over the PCB. Basically resurrection of the board will be impossible as a lot of fine tracks have ceased to exist and the schematic is unobtainable so repair of the tracks just can't happen.
Actually the microbee tracks can be repaired with fine wirewrap wire and careful soldering. Remove the green solder screen first and coat the areas with a flux solution of crushed Violin resin and 100% isopropyl alcohol, about 25% solution. Tin the ends of the tracks then restructure the tracks with fine wirewrap (0.4mm) A Maggy lamp or similar helps x5 magnification and a very steady hand. When the job is finished and deemed repaired remove the excess flux, dry and coat the repaired part of the board with spray on PCB protection varnish.