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 Assembly RG5-2189-000CN5 
Paper Output Sensor Assembly RG5-0475-060CN 8-1 4/4+ 
Paper Sensor Flag RB1-2133-000CN4/4+/5 
Paper Sensor Leaf Spring RB1-2139-030CN4/4+/5 
PC (Tray 1) Pickup Solenoid (SL 2) RH7-5074-000CN 8-6b 4 
PC (Tray 1) Pickup Solenoid (SL 2) RH7-5075-000CN 8-6b 4+/5 
PC (Tray 2) Pickup Solenoid (SL 1) RH7-5070-000CN 8-6a 4 
PC (Tray 2) Pickup Solenoid (SL 1) RH7-5071-000CN 8-6a 4+/5 
PC Tray (A4) C2085C8-14 4 
PC Tray (A4) C2085F8-14 4+ 
PC Tray (A4) C3926A8-14 5 
PC Tray (ltr) (Tray 2) C2085B8-14 4 
PC Tray (ltr) (Tray 2) C2085E8-14 4+ 
PC Tray (ltr) (Tray 2) C3925A8-14 5 
PCA, Sensor (PS4, PS5) RG5-0514-000CN 8-6b 4/4+/5 
Photo-Sensor (PS1, PS2) (Qty. 2) WG8-0291-000CN 8-6a 4/4+/5 
Photosensor (PS3) WG8-0291-000CN 8-9 4/4+/5 
Pin, Sensor Holder RB1-2179-000CN 8-6a 4/4+/5 
Plate, End RF5-0446-000CN 8-13 4/4+ 
Plate, End RF5-1675-000CN 8-13 5 
Plate, Grounding RB1-2106-000CN 8-4a 4/4+/5 
Parts and Diagrams  8-51 
						

							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 
Plate, Shield RF5-0471-000CN 8-4c 4 
Plate, Shield RF5-0746-000CN 8-4c 4+ 
Plate, Shield RF5-1647-000CN 8-4c 5 
Plate, Side Adjust RF5-0430-000CN4/4+/5 
PostScript Level 2 Emulation SIMM C2080A 4 
PostScript Level 2 Emulation SIMM C3129A 4+ 
PostScript Level 2 Emulation SIMM C3918A 5 
PostScript SIMM Package C3129-690014 
PostScript SIMM Package C3918-690014+ 
PostScript SIMM, Replacement Only C2080-69001 4 
Power Assembly (100/115V) C2001-69007 8-4b 4 
Power Assembly (100/115V) C2037-69006 8-4b 4+ 
Power Assembly (100/115V) RG5-0531-000CN 8-4b 4 
Power Assembly (100/115V) RG5-2499-000CN 8-4b 4+ 
Power Assembly (220/240V) C2001-69008 8-4b 4 
Power Assembly (220/240V) C2037-69007 8-4b 4+ 
Power Assembly (220/240V) RG5-0553-000CN 8-4b 4 
Power Assembly (220/240V) RG5-2500-000CN 8-4b 4+ 
Power Supply (100/110V) C2001-690078-1a 4 
Power Supply (100/110V) C2037-690068-1a 4+ 
8-52 Parts and Diagrams 
						

							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 RF5-0533-000CN 8-2 4 
Rear Door Assembly RF5-0733-000CN 8-2 4+ 
Rear Door Assembly RF5-1645-000CN 8-2 5 
Rear Door Latch RB1-2335-000CN 8-2 4/4+ 
Rear Door Latch RB1-3475-000CN 8-2 4+/5 
Rear Door Latch RB1-7890-000CN 8-2 5 
Rear Door Spring RS5-2219-000CN 8-2 4/4+ 
Rear Door Spring RS5-2571-000CN 8-2 5 
Rear Door Support Strap RB1-2354-000CN 8-2 4 
Rear Door Support Strap RS5-2219-000CN 8-2 4+/5 
Right Cover RB1-2346-000CN 8-2 4 
Right Cover RB1-3470-000CN 8-2 4+ 
Right Cover RF5-1644-000CN 8-2 5 
Right Front Cover RB1-7889-000CN 8-2 5 
Ring, Roller (2 ea.) FB1-0253-000CN 8-10 4+/5 
Ring, Roller (2 ea.) RA1-7584-000CN 8-10 4 
Rod RB1-2352-000CN 8-4b 4/4+ 
Rod RB1-7896-000CN 8-4b 5 
Roller, Guide RB1-2182-000CN 8-6a 4/4+/5 
Roller, Guide RB1-2616-000CN 8-11 4/4+/5 
Roller, Guides (6) RB1-2253-000CN 8-4d 4/4+/5 
Roller, Lower RB1-2264-000CN 8-10 4 
Parts and Diagrams  8-53 
						

							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 RF5-0349-000CN 8-4d 4/4+/5 
Roller, Upper RB1-2263-000CN 8-10 4 
Roller, Upper RB1-3516-020CN 8-10 4+/5 
Roller, Upper Delivery RF5-0534-000CN 8-8 4/4+ 
Roller, Upper Delivery RF5-1076-020CN5 
Rollers, Delivery, 4 ea. RB1-2299-030CN 8-8 4/4+/5 
Screw w/Washer, 4 ea. XA9-0585-000CN 8-4b 4/4+/5 
Screw w/Washer, M3x29.5 XA9-0668-000CN 8-4b 4+/5 
Screw with Washer (M3x8) (4) XA9-0591-000CN 8-3a 4/4+ 
Screw, 5mm hex head XA9-0574-000CN 8-4c 4/4+/5 
Screw, M3x3 XA9-0678-000CN 8-10 4+/5 
Screw, M3x4 XB6-7300-409CN 8-10 4 
Screw, M3x4 XB6-7300-409CN 8-4c 4 
Screw, M3x6 XA9-0617-000CN 8-4c 4 
Screw, M3x6 XA9-0670-000CN 8-4c 4+/5 
Screw, M3x6 XA9-0702-000CN 8-10 4+/5 
Screw, M3x6 XB2-8300-607CN 8-10 4 
Screw, M3x8 XA9-0591-000CN 8-11 4/4+/5 
Screw, Shoulder (M3) RS5-9055-000CN 8-10 4/4+/5 
Screw, Shoulder w/Washer (M3) 8-10 4+/5 
Screw, Shoulder w/Washer (M3)  RF5-0716-000CN 8-10 4/4+/5 
8-54 Parts and Diagrams 
						

							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, Torsion RB1-2122-000CN 8-4a 4/4+/5 
Shutter, Arm RB1-2111-030CN 8-4a 4/4+/5 
Shutter, Laser RB1-2080-000CN 8-4a 4/4+/5 
Spring, Compression RS5-2168-000CN 8-10 4 
Spring, Compression RS5-2218-000CN 8-4a 4/4+/5 
Spring, Compression RS5-2265-020CN 8-10 4+/5 
Spring, Compression, 4 ea. RS5-2185-000CN 8-8 4 
Spring, Compression, 4 ea. RS5-2267-000CN 8-8 4+/5 
Spring, Guide RB1-2286-000CN 8-10 4/4+/5 
Spring, Leaf RB1-2330-000CN 8-3a 4/4+ 
Spring, Leaf RB1-7893-000CN 8-3b 5 
Spring, Left Cartridge Guide RB1-5731-000CN 8-4a 5 
Spring, Roller, 4 ea. RB1-2302-000CN 8-8 4/4+/5 
Spring, Switch RB1-2358-000CN 8-4a 4/4+ 
Spring, Switch RB1-2966-000CN 8-4a 5 
Spring, Tension RS5-2180-000CN 8-10 4/4+/5 
Spring, Tension (Qty. 2) RS5-2170-000CN 8-4a 4/4+/5 
Spring, Torsion RB1-5732-000CN 8-4a 4/4+/5 
Static Eliminator RB1-2237-020CN 8-4a 4/4+/5 
Stop, Hinge RB1-2314-000CN 8-3a 4/4+ 
Parts and Diagrams  8-55 
						

							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 RG5-0468-000CN 8-4d 4/4+ 
Transfer Block Assembly RG5-2192-000CN 8-4d 5 
Transfer Guide Assembly RG5-0469-000CN 8-4a 4/4+/5 
Transfer Guide Assembly RG5-0469-020CN 8-1a 4/4+/5 
Upper Cover Assembly RG5-0458-000CN 8-3a 4 
Upper Cover Assembly RG5-0872-000CN 8-3a LJ4+ 
Upper Cover Assembly RG5-2186-000CN 8-3b 5 
Upper Frame RB1-3515-000CN 8-10 4/4+/5 
Upper Guide, Delivery RF5-0532-000CN 8-8 4/4+ 
Upper Guide, Delivery RF5-0647-000CN 8-8 5 
Washer, Grounding RB1-2287-000CN 8-10 4 
Washer, Grounding RB1-3528-000CN4+/5 
Weight RB1-2627-020CN 8-12 4/4+/5 
8-56 Parts and Diagrams 
						

							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 activated.  The
Switchback Solenoid moves the  Switchback Input Paper
Guide (2) , routing the paper into the Switchback mechanism.
The Switchback Stepper Motor (3)  then pulls the paper out of
the printer into the Switchback Assembly.  (The paper can be
seen coming out of the top of the Switchback Assembly.) 
As the paper moves through the Switchback Assembly, the spring
loaded switchback  Paper Reversing Guide (4)  and its attached
flag is moved, activating the  Switchback Paper Sensor (5) .
The paper continues to move out of the Switchback Assembly
until it passes the switchback Paper Reversing Guide. The
switchback Paper Reversing Guide returns to its original position
when the paper passes it.  The flag attached to the guide switches
the electrical state of the switchback paper sensor. This signals
the  Duplex Control PCA (6)  that the paper has advanced far
enough to reverse direction.  The Duplex Control PCA then
reverses the direction of the Switchback Stepper Motor, causing
the paper to reverse direction and move into the duplex  Holding
Tray (7) . 
Holding Tray
The Holding Tray, as the name implies, holds the paper which
has been printed on one side while the print engine prepares to
print the second side. The major components of the Holding Tray
are the  Holding Tray Input Stepper Motor (8) , the Holding
Tray Output Stepper Motor (9) , and the Holding Tray
Paper Detect Sensor (10) .
Duplexer   A -3 
						

							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 Duplex Control PCA will then turn on both the
Holding Tray Input Stepper Motor and the Holding Tray Output
Stepper Motor.  These motors will move the paper out of the
Holding Tray into the paper input of the print engine.  The paper
is then printed on the second side.  When the paper exits the
Fuser Assembly, the Switchback Input Guide routes the paper
directly to the printer’s output tray. 
3
4
2
5
1
89
7106
Figure A-2 Duplexer Major Components
A -4  Duplexer