Cassette paper-level and paper-presence detection ...................... 186
Multifeed prevention ....................................................................... 187
Multipurpose tray pickup ................................................................................. 188
Multipurpose tray last-paper detection ........................................... 189
Paper feed ....................................................................................................... 190
Skew-feed prevention ..................................................................... 191
Paper-type detection ...................................................................... 192
Feed-speed control ......................................................................... 193
Fusing and delivery unit ................................................................................................... 195
Loop control .................................................................................................... 195
Pressure-roller pressurization control ............................................................. 196
Duplexing unit .................................................................................................................. 197
Duplexing reverse and feed control ................................................................ 198
Jam detection ................................................................................................................................... 199
Optional input trays .......................................................................................................................... 201
Paper-feeder pickup and feed operation ......................................................................... 204
Scanner component ......................................................................................................................... 206
Product boards ................................................................................................................ 207
Scanner system block diagram ........................................................................................ 208
Scanner image-data path ................................................................................................ 209
Scanner power topology .................................................................................................. 210
Scanner power states ...................................................................................................... 211
Sensor topology ............................................................................................................... 212
Boards I/Os ...................................................................................................................... 215
Scanner operation flow .................................................................................................... 217
ADF .................................................................................................................................................. 221
Input tray .......................................................................................................................... 221
ADF simplex-printing operation sequence ....................................................................... 221
ADF duplex-printing operation sequence ........................................................................ 222
Multifeed operation .......................................................................................................... 223
End of a scan job operation ............................................................................................. 224
Paper pick and separation operation ............................................................................... 224
Deskew ............................................................................................................................ 225
6 Removal and replacement
Removal and replacement strategy .................................................................................................. 228
Introduction ...................................................................................................................... 228
Required tools .................................................................................................................. 229
Types of screws ............................................................................................................... 229
Service approach ............................................................................................................. 230
Before performing service ................................................................................................ 230
After performing service ................................................................................................... 230
Parts removal order ......................................................................................................... 231
viii ENWW