HP Laserjet 4 Manual

6Remove the (1) one-way gear shown in Figure A-21, callout 1.
NoteThe one-way gear must be reassembled correctly.
With the gear on the shaft, turn the gear
clockwise. The shaft should move the belt.
Turning the gear counter clockwise should result
in no movement of the shaft and belt.
7Remove the (1) E-clip from behind the first gear (see Figure
A-21, callout 2).
8Remove the (2) gears shown in Figure A-21, callouts 3 and 4.
9Slip the belt off the gears. 
Note Verify proper wire routing when...

Removing the Holding Tray Paper Sensor  
1Release the output holding tray.
2Remove the (2) screws from the stepper motor mount and
remove mount.  (This provides access to the paper sensor
latches.)
3Squeeze the (2) latch points of the paper sensor to release (see
Figure A-22). 
4Disconnect the connector and remove the paper sensor.
Figure A-22 Holding Tray Paper Sensor
A -26  Duplexer  

Removing the Switchback Assembly
1Pull out the pin located on the Power PCA side (see Figure
A-23, callout 1).
2Release the (1) E-clip on the upper pin near the retaining arm
(see Figure A-23, callout 2).
3Pull the retaining arm off the pin.
4Rotate the switchback assembly and remove.
5Unplug the connectors.
Figure A-23 Switchback Assembly Hinge Pins
Duplexer   A -27 

Parts and Diagrams for the Duplexer
The figures in this section illustrate the major subassemblies and
component parts of the HP LaserJet 4+/5 Duplexer. 
Note
Not all duplexer parts are orderable. The parts listed are the only
orderable parts. Parts that have no reference designator or part
number are not field-replaceable and cannot be ordered through
HP.
A -28  Duplexer  

Figure A-24 Duplex External Covers
Duplexer   A -29 

Ref Part # Notes Description
1 RA2-2061-000CN
RA2-2231-000CNLJ4+
LJ5Front Cover
2 RA2-2096-000CN
RA2-2232-000CNLJ4+
LJ5Left Cover
3 RA2-2097-000CN
RA2-2233-000CNLJ4+
LJ5Right Cover
4 RA2-2098-000CN
RA2-2237-000CNLJ4+
LJ5Rear Lower Cover
5 RG1-3508-000CN
RG1-3570-000CNLJ4+
LJ5Rear Cover Assembly
5A RA2-2100-000CN LJ4+ Latch
5B
RS1-2413-000CN
RS5-2571-000CNLJ4+
LJ5Compression Spring Table A-24 Duplex External Covers
A -30  Duplexer  

Figure A-25a Duplex Feeder Assembly (1 of 2)
Duplexer   A -31 

Figure A-25b Duplex Feeder Assembly (2 of 2)
A -32  Duplexer  

Ref Part # Notes Description
1 RA2-2069-000CN LJ4+/5 PCA Shield Plate
2
RA2-2070-000CNLJ4+/5
Static Eliminator sml
3 RA2-2072-000CN LJ4+/5 Timing Belt
4 RA2-2076-000CN LJ4+/5 Sensor Arm
5 RA2-2078-000CN LJ4+/5 Rod Crank
6
RA2-2079-000CNLJ4+/5
Front Cover Rod
7 RA2-2081-000CN LJ4+/5 Hold Tray Rear Guide
8 RA2-2082-000CN LJ4+/5 Hold Tray Front Guide
9 RA2-2085-000CN LJ4+/5 Front Guide
10
RA2-2115-000CNLJ4+/5
Stepped Scr M3 by 6.5
11 RA2-2126-000CN LJ4+/5 Static Eliminator
12 RB1-2114-000CN LJ4+/5 Foot (Qty...

Ref Part # Notes Description
25 RS1-2406-000CN LJ4+/5 Torsion Spring (Qty 3)
26
RS1-2407-000CNLJ4+/5
Torsion Spring
27 RS1-2409-000C N LJ4+/5 Tension Spring
28 RS1-7010-000CN LJ4+/5 Shaft
29 WG8-5210-000CN LJ4+/5 Photo Interrupter
30
RG1-3501-000CN
RG1-3582-000CNLJ4+
LJ5Duplex Control PCA
31
RF1-3817-00017LJ5
Duplex Roller Holder
A -34  Duplexer