HP LaserJet Pro M201n - Page 7

Table of contents
1 Theory of operation ....................................................................................................................................... 1
Basic operation ...................................................................................................................................................... 2
Major product systems ........................................................................................................................ 2
Product 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 ................................................................................................................................................ 4
Firmware ........................................................................................................................... 4
Memory use ....................................................................................................................... 5
PJL overview ........................................................................................................................................ 5
PML ...................................................................................................................................................... 5
LEDM overview .................................................................................................................................... 5
ACL overview ....................................................................................................................................... 6
Control panel ....................................................................................................................................... 6
USB flash drive .................................................................................................................................... 6
Engine-control system .......................................................................................................................................... 7
DC controller operations ..................................................................................................................... 8
Motors, fans, clutches, solenoids, switches, and sensors ............................................................... 10
Fuser-control circuit .......................................................................................................................... 14
Fuser failure detection ................................................................................................... 15
Fuser temperature control ............................................................................................. 16
Fuser heater protective function .................................................................................... 17
Pressure roller cleaning .................................................................................................. 17
Low-voltage power supply ............................................................................................................... 18
Overcurrent/overvoltage protection .............................................................................. 20
High-voltage power supply ............................................................................................................... 21
Laser/scanner system ......................................................................................................................................... 22
Laser failure detection ...................................................................................................................... 22
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