HP41C - 16 registers missing

[rprosperi]

Some things to try:

1. Have you tried the RAM module in all 4 slots?

2. Do you know that the slots work properly (e.g with a ROM module)? It's possible the connectors inside are dirty or damaged from a battery spill.

3. Can you test the RAM module on another 41C?

4. Try CAREFULLY cleaning the 'inside' contact side of the 'fingers' in the open side of the RAM module, perhaps they are dirty from age and/or a battery spill in an old 41 where it was stored. If you have it, clean the contacts with DeOxit RED; if not, try Isopropyl Alcohol.

Good luck, and please update this thread if/when you find the solution.