HP 2820, 2830, 2840 5 Removal and replacement

Step 6: secondary transfer...................................................................................	96
Step 7: separation................................................................................................	97
Fusing stage.........................................................................................................................	98
Step 8: fusing.......................................................................................................	98
Step 9: roller charging (auxiliary transfer belt cleaning roller).............................	98
Step 10: roller charging (transfer-belt cleaning roller).........................................	99
Step 11: transfer belt cleaning.............................................................................	99
Step 12: drum cleaning......................................................................................	100
Print cartridge......................................................................................................................	102
Imaging-drum E-label.........................................................................................................	103
Scanner and ADF functions and operation.........................................................................................	104
Scanner functions ..............................................................................................................	104
Scanner operation...............................................................................................................	104
ADF operation.....................................................................................................................	105
ADF paper path and ADF sensors.....................................................................................	105
ADF jam detection..............................................................................................................	106
Fax functions and operation................................................................................................................	107
PSTN operation..................................................................................................................	107
To receive faxes when you hear fax tones.........................................................................	107
The fax subsystem..............................................................................................................	107
Formatter in the fax subsystem..........................................................................................	108
LIU in the fax subsystem....................................................................................................	108
Safety isolation...................................................................................................	108
Safety-protection circuitry...................................................................................	108
Data path............................................................................................................	109
Hook state..........................................................................................................	109
Downstream current detection...........................................................................	109
Hook switch control............................................................................................	109
Ring detect.........................................................................................................	110
Line current control............................................................................................	110
Billing (metering) tone filters..............................................................................	110
Fax page storage in flash memory.....................................................................................	110
Stored fax pages................................................................................................	111
Advantages of flash memory storage ...............................................................	111
5 Removal and replacement
Chapter contents.................................................................................................................................	113
Removal and replacement strategy ....................................................................................................	114
Required tools.....................................................................................................................	114
Screws................................................................................................................................	114
Electrostatic discharge........................................................................................................	115
Before performing service...................................................................................................	116
After performing service......................................................................................................	116
Post-service tests................................................................................................................	116
Test 1 (print-quality test)....................................................................................	116
Test 2 (copy-quality test)....................................................................................	117
Test 3 (fax-quality test).......................................................................................	117
Test 4 (memory-card test)..................................................................................	117
Parts removal order............................................................................................................	118
User-replaceable parts........................................................................................................................	119

ENWW