HP Memory Enhancement technology................................................................82 PJL overview.........................................................................................................................82 PML.......................................................................................................................................82 Control panel.........................................................................................................................82 Scanner interface..................................................................................................................83 Engine-control system...........................................................................................................................84 DC controller PCA.................................................................................................................84 Motors and fans....................................................................................................................86 Motor and fan functions........................................................................................86 Ambient-temperature detection............................................................................87 Engine power supply circuit..................................................................................................87 Fuser control.........................................................................................................................88 Fuser over-temperature protection......................................................................89 High-voltage power supply...................................................................................................91 Low-voltage power supply ...................................................................................................92 Overcurrent/overvoltage protection......................................................................................94 Toner detection.....................................................................................................................94 Cartridge detection................................................................................................................94 Laser/scanner system...........................................................................................................................95 Laser/scanner control...........................................................................................................96 Image-formation system........................................................................................................................98 Print cartridge........................................................................................................................99 Cartridge memory................................................................................................99 Image-formation process....................................................................................................100 Pickup, feed, and delivery system.......................................................................................................102 Pickup-and-feed block........................................................................................................105 Printing from tray 1.............................................................................................106 Printing from tray 2.............................................................................................107 Media-size detection.........................................................................108 Cassette media-size detection.........................................108 Media-length detection.....................................................108 Media-width detection.......................................................108 Cassette pickup operation.................................................................108 Lifter-driver operation........................................................................110 Multifeed prevention..........................................................................110 Distance-between-pages adjustment................................................111 Media-skew prevention......................................................................................112 Feed-speed control............................................................................................114 Fusing and reversing/delivery block...................................................................................115 Fusing.................................................................................................................115 Face-down delivery............................................................................................115 Face-up delivery.................................................................................................116 Jam detection......................................................................................................................118 Pickup delay jam from tray 1..............................................................................118 Pickup delay jam from tray 2..............................................................................118 Pickup stationary jam.........................................................................................118 Fuser-delivery delay jam....................................................................................119 Fuser wrapping jam............................................................................................119 Fuser-delivery stationary jam when feeding regular-size media.......................119 Fuser-delivery stationary jam when feeding custom-size media.......................119 vii