Registration problem

[Abhi]

A vintage (early 1980s) Komori PQC is struck as follows:
1) Plate register moves the plate up and down but the display values on the PQC don't change,i.e. the reading is struck at 0.47 for all units.

The card is Nikki Denso made and problem is for all units.

Any tips on what may be wrong?

 

[turbotom1052]

check the potentiometers?

 

[Abhi]

check the potentiometers?

I'll be doing that.
But I observed that the reading reads 0.47 even if the input cable to the card is removed. For lateral, it becomes 0.00, but for circumferential it remains struck at 0.47.
Is it normal?