HP 8550mfp Service Manual - Page 426

Table 43. Sensor monitor test Designator 0 1 2 3 4 5 6 7 8 9 A Sensor name Registration roller paper sensor (PS1) Pick-up unit paper sensor (PS17) Separation sensor (PS5) Fusing delivery sensor (PS1903) Top (face-down) output bin delivery sensor (PS11) Tray 1 paper sensor (PS1301) Tray 2 sensor (PS1202) Toggles once. Trays do not lift during test. Tray 3 sensor (PS1201) Toggles once. Trays do not lift during test. Duplex paper sensor (PS24) Paper sensor in the duplexer in the output position (HP Color LaserJet 8550 only) Reverse sensor (PS26) Paper sensor in the duplexer at the reversing position (HP Color LaserJet 8550 only) Bit 0 of temperature/humidity sensor B Bit 1 of temperature/humidity sensor The ambient temperature and humidity sensor data are combined into 2 bits showing 4 states of temperature and humidity. 00 = Normal/normal 01 = High/high 10 = Normal/low 11 = Low/low See figure 57 on page 184 for more information on these sensors. Exiting the service mode Exit the service mode by cycling through the menu until EXIT SERVICE MODE is reached, and press SELECT. It is not necessary to turn the printer off and on again unless you have accessed the formatter diagnostics. 424 Chapter 7 - Troubleshooting EN