Parts Replacement
4-3
March 2008
Removing the Printed
Circuit Board
All of the remaining maintenance procedures discussed in this
chapter require removal of the printed circuit board. Refer to
Figure 4-1 on page 4-10 and Figure 4-2 on page 4-11 while
completing the following tasks:
1.
Remove the main power to the electronics console.
!WARNING!
The main power to the Model DF868 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
from terminal block
TB1
on the PC board. Remove the electrical
connectors from all installed option cards and terminal blocks.
Disconnect the twisted-pair display backlight cable from
connector
J2
on the left side of the PC 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.
6.
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 rear of the board.
Caution!
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 will break the component leads.
7.
Tilt the top of the printed circuit board forward, and mark the top
edges of the two ribbon-cable connectors. Then, remove these
cables from their connectors on the rear of the board.
8.
The printed circuit board is now free and may be removed to a
clean work area.
Summary of Contents for DigitalFlow DF968
Page 2: ......
Page 7: ...Chapter 1 ...
Page 23: ...Chapter 2 ...
Page 32: ...Chapter 3 ...
Page 42: ...Chapter 4 ...
Page 55: ...Appendix A ...
Page 56: ...Service Record Introduction A 1 Data Entry A 1 ...
Page 60: ...Appendix B ...