HP-41C service module question

[Diego Diaz]

Hi Jurgen, all,

I found the references about the ET-11967 wired memory module some time ago, and according to the (few) details from the Service Manual, my best guess it that it's just a double memory module internally wired.

This was required to have an HP-41C at full memory (320 reg.) while having the SM plugged. Obviously it becomes useless once the Quad Mem module was available.

I also built a replica of said ET-11697 and perform the tests in the manual to confirm it shows the expected results. It does :-)

Regarding the first problem you mentioned: MEMORY LOST on power on with SM plugged. It seems to be related to I/O port connector problem (assumed SM is OK) or CPU board.

Any other hints? Does the HP-41 under test show other symptoms when in operation?

Keep us posted.

All the best from Canary Islands.

Diego.