Hello,
Just want to share my experience on repairing a problem in my newly acquired Nagra T-audio with new type keyboard.
The problem was in the shuttle mode, it never worked. After some debugging, I suspected that corrupted data was stored in the backup memory, what I did is that I took away the backup battery and shorted the backup capacitor in order to be sure that no voltage is present. I attached the battery back and the machine got a "cold" hardware restart. After that, everything is working as expected.
If you have problems regarding the control logic, try to perform a cold restart as described above.
Also, thanks for Ki for his support.
Good luck!
Kind regards,
Hani