HP 4 Plus Manual

DescriptionPart #Fig.  # Printer 
Paper Feed Assembly RG5-0451-000CN,   4 
Paper Feed Assembly RG5-0451-000CN 8-6 4 
Paper Feed Assembly RG5-0877-000CN 8-6 4+ 
Paper Feed Assembly RG5-0877-000CN4+ 
Paper Feed Assembly RG5-2195-000CN 8-6 5 
Paper Feed Assembly RG5-2195-000CN5 
Paper Output Assembly RG5-0456-000CN 8-8 4 
Paper Output Assembly RG5-0456-000CN4 
Paper Output Assembly RG5-0886-000CN 8-8 4+ 
Paper Output Assembly RG5-0886-000CN4+ 
Paper Output Assembly RG5-2189-000CN 8-8 5 
Paper Output...

DescriptionPart #Fig.  # Printer 
Plate, Grounding RB1-2647-000CN 8-11 4/4+/5 
Plate, Length Adjustment RB1-2370-020CN 8-14 4/4+/5 
Plate, PCA Holding RB1-2365-000CN 8-4c 4 
Plate, PCA Holding RB1-3493-000CN 8-4c 4+/5 
Plate, Pressure RB1-7917-000CN 8-4a 5 
Plate, Pressure RB1-7918-000CN 8-4a 5 
Plate, Pressure RF5-0365-000CN 8-4a 4/4+ 
Plate, Pressure RF5-0366-000CN 8-4a 4/4+ 
Plate, Reinforcement RB1-3494-000CN 8-4c 4+ 
Plate, Reinforcement RB1-7892-000CN 8-4c 5 
Plate, Shield RB1-2338-000CN 8-4c 4...

DescriptionPart #Fig.  # Printer 
Power Supply (100/110V) RG5-0531-000CN 8-1a 4+/5 
Power Supply (100/110V) RG5-0531-000CN 8-1a 4 
Power Supply (100/110V) RG5-2499-000CN 8-1a 4+ 
Power Supply (100/110V) RG6-2499-000CN 8-1a 4+/5 
Power Supply (220/240V) C2001-690088-1a 4 
Power Supply (220/240V) C2037-690078-1a 4+ 
Power Supply (220/240V) RG5-0553-000CN 8-1a 4 
Power Supply (220/240V) RG5-2500-000CN 8-1a 4+ 
Rear Cover Assembly RG1-3508-000CN4+ 
Rear Cover Assembly RG1-3570-000CN5 
Rear Door Assembly...

DescriptionPart #Fig.  # Printer 
Roller, Lower RB1-3517-030CN 8-10 4+/5 
Roller, Lower Delivery RF5-0438-000CN 8-8 4 
Roller, Lower Delivery RF5-1077-030CN 8-8 4+/5 
Roller, MP Tray Pickup RB1-2127-000CN 8-6b 4/4+ 
Roller, MP Tray Pickup RB1-2205-000CN 8-6b 5 
Roller, Pickup RB1-2126-000CN 8-6b 4 
Roller, Pickup RB1-2632-000CN 8-12 4 
Roller, Pickup RB1-2650-000CN 8-12 4+ 
Roller, Pickup RB1-3477-000CN 8-6b 4+ 
Roller, Pickup RB1-7911-000CN 8-6b 5 
Roller, Pickup RB1-7983-000CN 8-12 5 
Roller, Transfer...

DescriptionPart #Fig.  # Printer 
Screw, w/Spring Washer XA9-0584-000CN 8-4c 4 
Screw, w/Spring Washer XA9-0670-000CN 8-4c 4+/5 
Screw, w/Washer, 2 ea XA9-0267-000CN 8-4b 4+/5 
Screw, w/Washer, 4 ea. FA9-1449-000CN 8-4b 4 
Sensor PCA RG5-0514-000CN 8-6b 4/4+/5 
Shaft RF5-0375-000CN 8-11 4/4+/5 
Sheet RB1-2312-000CN 8-4c 4/4+/5 
Sheet RB1-2313-000CN 8-4c 4/4+/5 
Shield, Font Cover RB1-2366-000CN 8-4c 4 
Shield, Font Cover RB1-3496-000CN 8-4c 4+ 
Shield, Font Cover RB1-7898-000CN 8-4c 5 
Shutter Spring,...

DescriptionPart #Fig.  # Printer 
Support, Cartridge RB1-2105-030CN 8-4a 4/4+/5 
Switch RB1-2119-000CN 8-5 4/4+ 
Switch RB1-7907-000CN 8-5 5 
Thermistor RH7-7045-000CN 8-10 4 
Thermistor RH7-7054-000CN 8-10 4/4+
Thermoswitch Assembly RG5-0474-000CN 8-10 4 
Thermoswitch Assembly RG5-0881-000CN 8-10 4+/5 
Toner Cartridge 92298A
Tool, hook RB1-7895-000CN 8-3b 5 
Top Cover Door RB1-2322-000CN 8-3a 4 
Top Cover Door RB1-3474-000CN 8-3a 4+ 
Top Cover Door RB1-7883-000CN 8-3b 5 
Transfer Block Assembly...

A 
Duplexer 
This Appendix contains a functional overview of the Optional
Duplexer, as well as step-by-step Installation and Removal &
Replacement instructions.
The Optional Duplexer, when used with the LaserJet 4 Plus/5
printer, allows printing on both sides of the paper. It may be used
with the optional 500-sheet Lower Cassette or with the printer
alone. 
NoteThe Duplexer works only with the LaserJet 4
Plus or LaserJet 5 printer.  It is not supported on
the LaserJet 4.
Duplexer   A -1 

Functional Overview
The Duplexer consists of two major assemblies; the Switchback
Assembly that is attached to the back of the printer and the
Holding Tray located directly under the printer (see Figure A-1.)
SWITCHBACK
ASSEMBLYOUTPUT TRAY
MP TRAY
PC  TR AY
DUPLEXER
OPTIONAL
500-SHEET
CASSETTE
HOLDING TRAY
Figure A-1 Duplexer Paper Path
A -2  Duplexer  

Duplex Printing
NoteThe bold text
  and numbers in the following
description refer to parts shown in Figure A-2. 
When the printer is operating in duplex mode, the print images
are printed in reverse order. Page two prints on the first pass of
the paper through the printer and page one prints on the second
pass through.
Switchback Assembly
To print the first pass, the paper goes through the printer paper
path, where it is developed and fused. As the paper exits the
fuser, the  Switchback Solenoid (1)  is...

As the paper moves from the Switchback Assembly, it is picked
up by the rollers that are operated by the Holding Tray Input
Stepper Motor. The Input Stepper Motor moves the paper into
the Holding Tray.  When the paper moves the flag that controls
the Holding Tray Paper Sensor, the Duplex Control PCA turns off
the Input Stepper Motor, and the paper stops moving. 
The paper remains in the Holding Tray until the print engine
signals the Duplex Control PCA that it is ready to print the
second side.  The...