Table of contents
1 Theory of operation
Basic operation ..................................................................................................................................... 2
Major printer systems .......................................................................................................... 2
Printer block diagram ........................................................................................................... 2
Sequence of operation ......................................................................................................... 3
Normal sequence of operation ............................................................................ 3
Formatter-control system ..................................................................................................................... 4
Sleep mode .......................................................................................................................... 4
Input/output .......................................................................................................................... 4
CPU ..................................................................................................................................... 4
Memory ................................................................................................................................ 5
Optional hard disk ............................................................................................... 5
Firmware ............................................................................................................. 5
Nonvolatile memory ............................................................................................ 5
PJL overview ....................................................................................................................... 5
PML ..................................................................................................................................... 5
Control panel ....................................................................................................................... 5
Engine-control system .......................................................................................................................... 6
Motors, fans, clutches, solenoids, switches, and sensors ................................................... 7
DC controller operations .................................................................................................... 14
Fuser-control circuit ........................................................................................................... 16
Fuser failure detection ....................................................................................... 17
Fuser temperature control ................................................................................. 18
Fuser protective function ................................................................................... 19
Low-voltage power supply ................................................................................................. 20
Overcurrent/overvoltage protection ................................................................... 21
High-voltage power supply ................................................................................................ 22
Formatter ........................................................................................................................... 23
Formatter heartbeat LED .................................................................................. 23
DIMM slots ........................................................................................................ 23
Laser/scanner system ........................................................................................................ 24
Laser failure detection ....................................................................................... 25
Image-formation system ..................................................................................................................... 26
Electrophotographic process ............................................................................................. 26
ENWW v
