Posts: 451
Threads: 107
Joined: Nov 2005
Some simple tests first
NB these are based on HP41 HPIL experience
Are your cables OK? Try looping them from one connector on the 71 to the other. The 71 shouldn't find the device, but it shouldn't report a broken loop either. (do this with each cable).
This should do a basic test of the 71 and the cables.
If this works, then start to suspect the Cassette drive HPIL interface (which you probably already do anyway :-).
There are a number of things that could have gone wrong. I have some vague details of how HPIL worked, but let someone else with experience help out here (all my stuff works, and if it aint broken...)
Posts: 17
Threads: 1
Joined: Jan 1970
The 9114 uses a sealed lead-acid cell as the power supply. If the cell is bad (expected in equipment this age), it is possible that the voltage supplied to the 9114 will vary as wildly as the output of an unfiltered rectifier. This will certainly cause the self-test to fail. Open the battery pack, take out the lead-acid cell, apply 6V (watch polarity) at the battery connectors (while having the battery case & connectors inserted into the 9114-- you figure out how to do this) and test the drive again. If it works, the culprit is the sealed lead-acid cell.