HP Laserjet 5 Service Manual

General Timing Diagram - HP LaserJet 5L
Figure 5-7
5 - 20 Functional Overview 

General Timing Diagram - HP LaserJet 6L
Figure 5-8
5
Functional
Overview
Functional Overview 5 - 21 

5 - 22 Functional Overview 

6
Removal and Replacement
Contents
Removal and Replacement Strategy .  . .  . .  . .  . .  . .  . .  . .  . .  . .  . .  . . 6-3
Required Tools . .  . .  . .  . .  . .  . .  . .  . .  . .  . .  . .  . .  . .  . .  . .  . .  . . 6-4
Installing Memory Cards (DRAM) .  . .  . .  . .  . .  . .  . .  . .  . .  . .  . .  . . 6-5
Covers and Doors . .  . .  . .  . .  . .  . .  . .  . .  . .  . .  . .  . .  . .  . .  . .  . . 6-6
Back Cover . .  . .  . .  . .  . .  . .  . .  . .  . .  . .  . .  . .  . .  . .  . ....

6 - 2 Removal and Replacement 

Removal and Replacement Strategy
This chapter documents removal and replacement of Field Replaceable Units
(FRUs) only. Exchange assemblies should be sent to SMO for repair.
Replacement is generally the reverse of removal. Occasionally, notes are included to
provide direction for difficult or critical replacement procedures.
WARNING!Unplug the power cord from the power outlet before attempting to service the
printer. If this warning is not followed, severe injury may result.
Never operate or service the...

Required Tools
·#2 Phillips screwdriver with a magnetic tip
·5.5 mm hexhead nutdriver
·small flathead screwdriver
·needlenose pliers
CautionA Posidriv screwdriver will damage the printer’s screw heads. Use Phillips only.
Figure 6-1 shows the difference between a Phillips and a Posidriv screwdriver. Note
that a Phillips tip has more beveled surfaces.
Phillips and Posidriv screwdrivers
Figure 6-1
6 - 4 Removal and Replacement 

Installing Memory Cards (DRAM)
1Unplug the power cord from the printer. You
should not install a memory card while the
printer is in SleepMode.
2Open the Printer Door, remove the toner
cartridge, and close the Printer Door. Protect
the toner cartridge from light while you are
working on the printer.
3Remove any paper in the paper tray. Gently
tip the printer onto its side so that the memory
cover is on top as shown in Figure 3.
4Remove the Memory Expansion Cover by
carefully pulling the tab out and away...

Covers and Doors
Back Cover
1Unplug the power cord and remove the parallel cable from the back of the printer.
2Remove the toner cartridge.
3Lift the Input Extender assembly.
CautionYou must lift the Input Extender when the covers are removed or it will break. After
you have removed the covers, leave the Input Extender in this lifted position for
ease of replacement.
4Remove the (3) screws (Figure 6-2, callout 1).
Back Cover Removal (1 of 2)
Figure 6-2
6 - 6 Removal and Replacement 

5Separate the rear panel from the main cover, pulling the lower corners away from
the printer first. Then, insert the small flathead screwdriver into the openings at the
top to pop the upper corners (Figure 6-3, callout 1).
6Remove the cover by grabbing it on both sides and pulling it straight back with a
firm pull (Figure 6-3, callout 2).
Back Cover Removal (2 of 2)
To reinstall
Make certain the Input Extender is up.
Figure 6-3
6
Removal and
Replacement
Removal and Replacement 6 - 7