GE DigitalFlow DF968, Service Manual

Page: 50 / 78

Parts Replacement 4-7
March 2008
Installing the Printed
Circuit Board
Whether the printed circuit board was removed for replacement or for
one of the other procedures discussed in this chapter, reinstallation of
the printed circuit board is the final step in the process. Refer to
Figure 4-1 on page 4-10 and complete the following steps:
Caution!
During this procedure, be very careful not to damage the
vertical components along the top edge of the printed
circuit board (see Figure 4-2 on page 4-11). Severe or
repeated bending of these components will break their
leads.
1. Position the printed circuit board within the electronics console
with the top edge tilted forward. Insert the display ribbon cable
and keypad ribbon cable connectors into their sockets on the rear
of the printed circuit board. See Figure 4-1 on page 4-10 and
Figure 4-2 on page 4-11 to identify the cables and sockets. Note
that the keypad cable connects to the upper socket and the display
cable connects to the lower socket.
IMPORTANT:
The ribbon cables must be installed with the edges
that were marked during removal oriented toward the
top of the printed circuit board.
2. Carefully position the printed circuit board up against the eight
standoffs in the enclosure. Do not damage the transformers and
any installed option cards as they are maneuvered between the
standoffs.
3. Loosely install the three long standoffs on the right side of the
printed circuit board and the two short standoffs (or screws) along
the bottom edge of the printed circuit board.Then, install only the
top and bottom short standoffs on the left side of the printed circuit
board.
4. Insert the free end of the green grounding strap between the
printed circuit board and the middle standoff beneath the left side
of the board. Making sure to capture the grounding strap lug
between the printed circuit board and the standoff beneath it,
install the remaining short standoff on the left side of the printed
circuit board. Securely tighten all eight standoffs and/or screws.
IMPORTANT:
Correctly installing the grounding strap may require
some patience, but resist the temptation to place the
grounding strap on top of the printed circuit board.