HP Laserjet 4 Manual

Removing the High Voltage Contact Assembly
and Feed Guide Assembly
NoteThe following procedures are difficult and the
components are damaged easily.  The tolerances
between the parts are close and several attempts
may be necessary before the procedure is
complete.
1Perform all the steps of “Accessing the High Voltage Contact
Plate/Feed Guide Assembly” in the order given.
2Press the tab shown in Figure 6-56 to release the gear cover.
3Release the (5) latches that hold the Contact Plate in place
(see...

Replacing the High Voltage Contact
Assembly/Feed Guide Assembly   
The Toner Cartridge Guide Plate and the High Voltage Contact
Assembly/Feed Guide Assembly must be installed together.
Allow plenty of time to perform this procedure because several
iterations of the process may be necessary.  
1Set the contact assembly over its mounting holes.
2Slide the Toner Cartridge Guide Plate into position on a
diagonal line (see Figure 6-57).
3Working the two parts together, lift the rear of the HVCP to
provide...

Interconnect PCA Removal 
The Interconnect PCA is a connector board that connects the
Power Supply and the DC Controller with the the Fuser
Assembly. The Fuser Assembly connects directly into the
Interconnect PCA. The Power Supply and the DC Controller have
wiring harnesses that connect them to the Interconnect PCA.
NoteRe-assembly of the the Interconnect PCA requires
a small tie-wrap. Be sure to have a tie-wrap
available before beginning the disassembly.
Remove the interconnect as follows:
1Remove the...

NoteAccess the Interconnect PCA Housing by laying
the printer on the rear of the printer chassis.  
4Disconnect the Interconnect Cable connector from the DC
Controller (J210 on LJ4, J213 on LJ4+/5). Remove the cable
from its retainer.
5Release the bottom or rear-most latch (see Figure 6-59),
callout 1) holding the arm of the Interconnect PCA housing to
the sheet metal.
6Rotate the bottom (rear) of the PCA housing up (toward the
front) to release the housing from the printer.
(continued on next page)...

NoteThe AC Connector has polarity. Note the
orientation of the AC Connector before removing
it. This is required in order to install the
connector with the same polarity during assembly
(see Figure 6-60). 
7Release the AC Connector from the sheet metal with
needle-nose pliers.  Service Hint: Use a 5mm nut driver to
press the AC Connector retaining pins from the sheet metal. 
Figure 6-60 Correct Orientation of AC Connector (Notch at
Upper Left)
6-71 Removal and Replacement 

6-72 Removal and Replacement 

7
LaserJet 5 Error Map
The LaserJet 5/5M/5N printer has error messages that are
similar to the LaserJet 4/4M/4+/4M+.  Use the following table to
look up the LJ5 error and take the recommended action.  If the
recommendation is to see another error, for example See 00
POWERSAVE, look up the recommendation for that error in the
Printer Message Troubleshooting section (Tables 7-1 and 7-2).
NoteThe LaserJet 5 printer’s Go  key replaces both the
Online and  Continue keys previously used to
resolve some of the...

Message on LJ 5/5M/5N Recommendations
INCOMPATIBLE TRAY 3 INSTALLEDIndicates that a lower cassette has been
installed that is not compatible with the
LJ5. Press  GO to clear the error.  The
tray will not appear in any control panel
or PJL messages.
INITIALIZING (powerup only) See 05 SELF TEST 
INSTALL TONER CARTRIDGESee 14 EP CART
INSTALL TRAY 2See PC INSTALL
INSUFFICIENT MEMORY, JOB CLEAREDSee W3 JOB ABORTED
INSUFFICIENT MEMORY, PRINTING AT
300 DPISee W4/7 JOB 300/[page protect size]
MANUALLY FEED...

Message on LJ 5/5M/5N Recommendations
REMOVE PAPER JAMSee 13 PAPER JAM
REQUESTED LANGUAGE NOT AVAILABLESee W2 INVALID PERS
RESETTING ACTIVE I/OSee 07 RESET
RESETTING ALL I/OSee 07 RESET
RESTORING FACTORY SETTINGSSee 08 COLD RESET
TONER LOWSee 16 TONER LOW
TRAY 2/3 EMPTYIndicates Tray 2 or 3 has run out of paper
and has not been selected as the current
job’s paper source.  If the problem
persists, check for a binding sensor flag
or replace the appropriate sensor.
TRAY x LOAD [paper or envelope size]See xx...

7-D  LaserJet 5 Error Map