Removing The Printed Circuit Board - GE DigitalFlow GC868 Service Manual

Removing the Printed
Circuit Board
Parts Replacement
All of the remaining maintenance procedures discussed in this
chapter require removal of the printed circuit board. To accomplish
this task, see Figure 4-1 on page 4-10 and Figure 4-2 on page 4-11
and complete the following:
1. Remove the main power to the electronics console.
The main power to the Model GC868 must be
disconnected before proceeding.
2. Open the electronics console. For LVD compliant units, remove
the two mounting screws and lift the clear plastic shroud out of the
electronics console. Remove the six mounting screws and lift the
main aluminum shroud out of the electronics console.
3. Disconnect the main power leads and the PC board ground wire
TB1
from terminal block
electrical connectors from all installed option cards and terminal
blocks. Disconnect the twisted-pair display backlight cable from
J2
connector on the left side of the printed circuit board.
4. Using a 3/8 in. nutdriver or open-end wrench, remove the three
short standoffs along the left side of the main circuit board and the
three long standoffs along the right side of the main circuit board.
5. While supporting the printed circuit board, remove the two screws
or standoffs along the bottom edge of the printed circuit board.
Note: For an LVD compliant meter with the clear plastic shroud
over the electrical connectors, there will be standoffs in these
two locations. For meters not equipped with this shroud, there
will be Phillips head screws in these two locations.
During this procedure, be very careful not to damage the
upright 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
6. On newer units, unscrew the green grounding strap from its
location between the fuse holder and power terminal block, taking
care not to lose the attached washer and nut.
7. Carefully lift the printed circuit board out of the enclosure.
Continue to support the printed circuit board, as the keypad and
display cables are still connected to the bottom of the board.
!WARNING!
on the printed circuit board. Remove the
Caution!
leads.
April 2008
4-3