Hello,
I just bought an old non-working HP67 in a garage sale yesterday, and i'd REALLY like to revive it. I kinda got attached to it even after one day :)
It seems like the battery leaked into the PCBs, most of them (mainly the one with the main controller) were corroded. I cleaned what I could very carefully, and changed the battery (with standard 3 AA batteries).
The screen now displays a line of _ (underscores) characters, except one digit (which might be broken). The keys have no action, neither has the prgm/run switch.
Does someone know what makes it display _, and what that indicates? Which part might be working/broken, so I can narrow down my search to the defective part. Is there hope? What do you think? Could you give me general advices on repairing this beautiful little toy?
Note: I wasn't so careful in the cleaning of the card reader part (the motor is even unplugged). Can it be the cause of the _?
Thanks in advance,
--Matthias