Originally Posted by
slimslob
vsp and vsdp are readings taken by the p sensor (ID sensor) immediately following the ID patch. vsdp is used for design purposes only. PWM is calculated during developer initialization and process control. It has to do with the voltage/current applied to the emitter of the p sensor in order to get a valid reading for the surface of the drum prior to the ID patch.
That all said, clean the p sensor. It is located in the PTR unit directly below the transfer roller. The sensor gets dirty and process control raises PWM. When PWM is increased, the ID patch looks lighter and process control increases the toner density causing back ground.
Bookmarks