Hello and asking for help with HP 67 power unit

[Tapti]

Dear all,
there is some continuation in the story so far. Sure enough, the spontaneous healing of which I reported last time was not for long. After some days of working the calculator once again showed the symptoms described. And this even more seriously, there is now no time period of operation after switching on as it was in the beginning of my work on the unit. Directly from the start it showes just some nonsense / flickering / fading seen from the display. So I decided to buy a new mainboard from Tonys workshop. After about two month it finally made its way from Australia to Germany. I just plugged it in before some minutes and what should I tell you ? It's working absolutely flawless from what a can say so far. Many many thanks to you, Tony, it' really a great work !
As soon as I get the taxes back from 2020, I will order another unit just as a spare for the original board, which is still working in my other 67.
Now I will lean towards the magnetic card reader. The gummi wheel
have been changed by somebody in advance. Nevertheless there is some work left: The card reader motor is running continuously and do not stop unless the calculator is switched off ! Perhaps some dirty micro switches ? Or can it be an electronic problem situated on the long narrow board connecting the main board to the card reader unit ? Should I exchange the rest of the tantalums ? Did somebody of you observed this behaviour, too ?
Anyway I'm just very happy to see my 67 operating my 'Hello World' program beeing counting up to infinity or better until the batteries will be empty ;-)
Best regards,
Stefan