HP-65 more on the card reader

[albertofenini]

Hi everyone,

few more tests that we did on the S/N 1511A01736 :
1. we rebuilt completely from scratch another card reader, everything, a new reinforced motor,
"new" components, "new" motor all coming from some spare material we have.
The result was, however, exactly the same.
2. We swapped the plastic chassis, including battery terminals and brass switches from another HP-65.
The result was, however, exactly the same
3. We mounted a 10K Ohm trimmer instead of the usual resistor (which measure 5,58 K Ohm in this unit).
Playing with this trimmer we were able to change the speed from almost nothing to maximum speed.
In same cases Channel WA (which is normally working) didn't report anything at all, while channel WB was
either "mute" or showed the usual erratic behavior

The only thing we cannot change is the keyboard plate, we have a spare one from our initial restoration project,
but it's missing Anode and Cathode drivers and we don't want to transplant these since it is too risky.

Remember we already swapped back and forth different logic boards without any improvement.

Thanks for any thoughts you may want to share with us !
Take care !