HP LaserJet 4 Service Manual - Page 157

Caution, DRAWING, DESCRIPTION, PURPOSE, Table 6-2

Page 157 highlights

Table 6-2 describes the screws used in the printers, and provides guidelines to help determine where each type of screw is used. The screws can vary in length depending on the thickness of the material being fastened. Typically, plated screws are used in areas visible to the customer, and black screws are used in all other areas of the printer. Always note where each type of screw is located and replace each one into its original location. Table 6-2 Printer Hardware Descriptions DRAWING DESCRIPTION Threaded Phillips screw with lock and flat washer PURPOSE Used to fasten metal or plastic to threaded plastic or metal. Threaded Phillips washer head Used to fasten metal or plastic screw to metal when high torque is required. Threaded Phillips w/captive star washer Used to fasten metal to metal when good electrical contact is needed. Self-tapping Phillips screw Used to fasten metal or plastic to plastic mainframes. Caution To install a self-tapping screw, first turn it counter-clockwise to align it with the existing thread pattern, then carefully turn clockwise to tighten. Do not over-tighten. If a self-tapping screw-hole strips, repair of the screw-hole or replacement of the affected assembly is required. In the removal and replacement procedures that follow, the number inside the parentheses, such as (4), refers to the number of screws you must remove. Removal and Replacement 6-3

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Table 6-2 describes the screws used in the printers, and provides
guidelines to help determine where each type of screw is used.
The screws can vary in length depending on the thickness of the
material being fastened.
Typically, plated screws are used in areas visible to the customer,
and black screws are used in all other areas of the printer.
Always note where each type of screw is located and replace each
one into its original location.
Caution
To install a self-tapping screw, first turn it
counter-clockwise to align it with the existing
thread pattern, then carefully turn clockwise to
tighten.
Do not over-tighten.
If a self-tapping
screw-hole strips, repair of the screw-hole or
replacement of the affected assembly is required.
In the removal and replacement procedures that follow, the
number inside the parentheses, such as (4), refers to the number
of screws you must remove.
DRAWING
DESCRIPTION
PURPOSE
Threaded Phillips screw with
lock and flat washer
Used to fasten metal or plastic
to threaded plastic or metal.
Threaded Phillips washer head
screw
Used to fasten metal or plastic
to metal when high torque is
required.
Threaded Phillips w/captive
star washer
Used to fasten metal to metal
when good electrical contact is
needed.
Self-tapping Phillips screw
Used to fasten metal or plastic
to plastic mainframes.
Table 6-2
Printer Hardware Descriptions
Removal and Replacement 6-3