Lexmark MS821

Options configurations..................................................................................................................................859
Theory of operation.................................................................................. 861
Print cycle operation....................................................................................................................................... 861
Flowchart ......................................................................................................................................................................861
Electrophotographic (EP) process..........................................................................................................................861
Fresh toner delivery drive .......................................................................................................................................867
Main drive....................................................................................................................................................................868
Printer operation............................................................................................................................................. 869
Printer sections ..........................................................................................................................................................869
Printer paper path rollers ........................................................................................................................................870
Printer paper path sensors ......................................................................................................................................871
Tray pick and lift drive ..............................................................................................................................................872
MPF pick drive............................................................................................................................................................873
Lower transport drive ...............................................................................................................................................874
Main drive....................................................................................................................................................................875
Fuser drive ..................................................................................................................................................................876
Upper redrive drive...................................................................................................................................................879
Duplex transport drive ..............................................................................................................................................881
Optional 250- and 550-sheet tray operation..........................................................................................882
250‑ and 550‑sheet tray paper path rollers ......................................................................................................882
250‑ and 550‑sheet tray paper path sensors ...................................................................................................883
Paper presence and size detection......................................................................................................................884
Tray pick and lift drive ..............................................................................................................................................885
Transport drive ...........................................................................................................................................................886
Optional 2100-sheet tray operation...........................................................................................................888
2100‑sheet tray elevator drive...............................................................................................................................888
2100‑sheet tray pick drive.......................................................................................................................................889
2100‑sheet tray transport drive ............................................................................................................................ 890
Optional output expander operation..........................................................................................................891
Output expander paper path ..................................................................................................................................891
Output expander diverter drive.............................................................................................................................892
Output expander transport drive ..........................................................................................................................893
Optional high capacity output expander operation...............................................................................894
High capacity output expander paper path .......................................................................................................894
HCOE diverter and transport drive.......................................................................................................................895
Optional mailbox operation..........................................................................................................................896
Mailbox paper path rollers ......................................................................................................................................896
Mailbox paper path sensors ...................................................................................................................................897
Mailbox diverter drive...............................................................................................................................................898
Mailbox transport and exit drive............................................................................................................................899
Optional staple, hole punch finisher operation...................................................................................... 900
Staple, hole punch finisher (SHPF) layout.......................................................................................................... 900
4064
Table of contents
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