sir my heidel berg sm72 machine after ink dect reset when ink level goes above two total spread can

sir my heidel berg sm72 machine after ink dect reset when ink level goes above two total spread can you help me why i set protential meter to zero

 

Remove motor and pot. Turn lead screw to fully closed position. Back off from closed position approximately 3/4 turn. With power off, disconnect old motor and pot, connect (electrically) new pot, turn on CPC and rotate pot (while another person watches readout until pot reads back “0” position on LED readout. Reconnect all components mechanically. It’s been awhile since I’ve done this, I think that would be it.