I have an HP-29C which does not show any display at all. The previous owner stated that it did work the last time he used it, but the battery pack was dead. When I replaced it with a good pack, I still get no display at all. The original batteries were badly corroded, and I fear he may have plugged in the AC adaptor and damaged it.
Anyway, can anyone comment on the failure mode? I know that there are particular chips in this beast which are likely to be fried if the voltage is allowed to spike at all. In this case, is the failure mode no display at all, or is it something else?
Things I have tried:
1. Connected a 3V supply directly to the terminals.
2. Opened the case and verified 3V on the PCB when the power switch is on.
No result from either.
Any advice is appreciated. I would sure love to bring this one back to life.
Don