HP 41 card reader repair questions

[Dave Britten]

I got a relatively cheap "for repair" 41 card reader, and it looks like someone attempted a repair on it in the past (not with the cleanest of results). I replaced the card transport roller, and also had to put a drop of superglue into the clutch/slip collar on the motor shaft, as it was slipping. It's pulling cards through just fine now, but it generally reports "MALFUNCTION" when trying to read anything. I don't see any errors when writing, but I don't have another 41 card reader to test the results on.

I opened it up enough to clean off the read/write head with a little alcohol, and I noticed there were only two of the long, thin spring contacts under the PCB attached to the reader mechanism, when it looks like there are contacts and a slot for a third one. Are there supposed to be three under there, and the previous owner lost one in a ham-handed repair attempt? Or did HP redesign the reader to only need two spring contacts? Serial number starts with 1936A, if that matters.

The one that looks like it's missing is the one that the card would trigger second, i.e. the first one that detects write enable is there, and there's one that the card hits just as it advances past the roller, but there's a place for a contact that would be triggered just as the card gets to the roller, and that one is gone.