I have DC 5252.When it in Service mode (service interlock that located in upper left corner behind front doors is on) press print test pages and make copy.When serice interlock is off press shows Close digital press doors message. I check doors sensors it is OK. I check fuse on DIST1 PWB, it is OK.When i check voltage in sensors it shows 24V when service interlock is ON and 5V when Service interlock is OFF. Tech doc says that voltage must be 24 V. Maybe problem in power supply (LVPS 4)?