GE DigitalFlow DF968, Service Manual

Page: 68 / 78

Optional Enclosures B-7
March 2008
Rack Mount LCD Display
Replacement (cont.)
7. Fasten the display shroud to the front panel with the four sets of
nuts/washers.
Caution!
Do not overtighten the nuts or damage to the mounting
threads may occur.
8. After checking for any loose hardware that may have fallen into
the enclosure, reinstall the top panel on the meter and secure the
panel in place with the four screws previously removed.
The Model DF868 flowmeter may now be placed back into service.
Reconnect the main power and resume taking measurements.
Note:
Be sure to record the LCD Display replacement in Appendix
A,
Service Record .
Rack Mount Printed
Circuit Board
Replacement
If troubleshooting procedures have indicated a defective printed
circuit board, follow the instructions in this section to replace the
defective board with a new one.
Circuit Board Removal
Refer to Figure B-2 on page B-11 and complete the following steps:
1. After disconnecting the main power to the meter, remove the top
panel from the enclosure by removing the four screws indicated.
!WARNING!
The main power to the Model DF868 must be
disconnected before proceeding.
2. Disconnect all external option card connectors at the rear panel of
the meter. Then, remove all installed option cards from the printed
circuit board, as described earlier in this chapter.
3. Disconnect the main
POWER LEADS
from the screw terminals at the
rear of the printed circuit board. Make a sketch of the terminal
block and the locations of the black, white and green power leads
to assist in reinstallation on the new circuit board.
4. Remove the
RS232
,
ANALOG OUT
and
TRANSDUCER
connectors
from the printed circuit board. Use a marker to identify pin #1 on
the right side (keypad side) of these connectors.