The Non A is easy, just hot wire it , replace battery, with a non grounded soldering pencil or tiny propane iron to prevent grounding out the RAM pin 24, scope is not plugged in ! IF the scope is the A model this tactic is not going to work , so you just hot wire the actual pin 24/12 . or if the data is still good inside the BAT/RAM then unsolder it ,same way as above and then back it up using any 27C256 Eprom programmer, to hex files , then reprogram then DALLAS chip. and solder it back in, using the same trick using a fully insulated soldering pencil ( use ground strap on you foot or arm to avoid ESD damage. Key factor here is not grounding pin 24 ever.