P4L60 Electrometer Reading >975 V dc

Eos Lists 2 possible causes, 1.The GROUND BRUSHES are not contacting the IMAGE LOOP. and 2. The GRID is not connected to the PRIMARY POWER SUPPLY. What I found was the Electrometer INTERFACE BOARD when I ran charger gap setup it had a voltage reading of 1000 when it should have been 575 +- 10