Table of contents
1 Theory of operation .......................................................................................................... 1
Basic operation ........................................................................................................................ 2
Function structure ...................................................................................................... 2
Operation sequence .................................................................................................. 2
Engine control system ............................................................................................................... 4
DC controller PCA ..................................................................................................... 5
Motor control ............................................................................................. 7
Motor locations ........................................................................... 7
Failure detection ......................................................................... 8
Fan control ................................................................................................ 9
Fan locations .............................................................................. 9
Failure detection ....................................................................... 10
Low-voltage power-supply PCA ................................................................................. 11
Over-current/over-voltage/overload protection ............................................ 12
Safety interruption .................................................................................... 12
Power supply voltage detection .................................................................. 13
Sleep mode ............................................................................................. 13
Power supply illumination control ............................................................... 13
High-voltage power-supply PCA ................................................................................ 14
Fuser control ........................................................................................................... 16
Fuser temperature control .......................................................................... 18
Fuser heater protective function .................................................................. 18
Fuser failure detection ............................................................................... 19
Pressure roller cleaning ............................................................................. 20
Laser scanner system .............................................................................................................. 21
Laser scanner failure detection .................................................................................. 22
Laser scanner safety function .................................................................................... 22
Image-formation system ........................................................................................................... 23
Image-formation process .......................................................................................... 25
Latent-image formation block ..................................................................... 25
Step 1: Primary charging ........................................................... 25
Step 2: Laser-beam exposure ...................................................... 26
ENWW
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Summary of Contents for LASERJET ENTERPRISE MFP M725dn
Page 1: ...LASERJET ENTERPRISE MFP M725 Troubleshooting Manual M725z M725dn M725f M725z ...
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Page 3: ...HP LaserJet Enterprise MFP M725 Troubleshooting Manual ...
Page 6: ...iv Conventions used in this guide ENWW ...
Page 32: ...xxx ENWW ...
Page 142: ...110 Chapter 1 Theory of operation ENWW ...
Page 457: ...4 Close the fuser jam access cover 5 Close the fuser door ENWW Clear jams 425 ...
Page 475: ...1 Lift the document feeder latch 2 Open the document feeder cover ENWW Clean the product 443 ...
Page 516: ...484 Appendix A Service and support ENWW ...
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Page 546: ... 2013 Hewlett Packard Development Company L P www hp com CF066 91023 CF066 91023 CF066 91023 ...