Lexmark X500n Service Manual - Page 202

7100-XXX Electronic components Printer engine sensor locations Name Paper size sensor Registration sensor Fuser exit sensor Tray empty sensor OPC marker sensor Toner empty sensor Waste toner sensor Temperature sensor for fuser unit Output tray full sensor Toner key sensor Toner density sensor Room temperature thermistor sensor Transfer unit sensor Code PSU PT1 PT2 PEU PBS TPD/TTR WTS (LED/TR) TH PFUL TNK TDS RTS TBS Detects paper size. Function Detects whether paper is fed from paper drawer. Detects when paper exits from rear cover assembly. Detects if paper is loaded in paper drawer. Detects connecting position of OPC belt. Detects if any toner cartridge is empty. Detects when waste toner bottle is full. Thermistor that detects fuser temperature. Detects when paper exit tray is full. Detects presence of toner cartridge. Detects toner density of images formed on the transfer belt surface. Detects ambient room temperature. Detects irregular rotation of transfer belt. 5-4 Service Manual