Appendix B. Optional Enclosures
B-3
DigitalFlow™ GC868 Service Manual (1 and 2-Channel)
6. Place the metal bracket over the option cards, making sure that all installed
option cards are inserted into the plastic card guides in the bracket. The bracket
must be oriented so that the six card guides are directly above the six sockets on
the printed circuit board (
do not
install the bracket rotated 180° out of position).
Secure the metal bracket to the printed circuit board with the four plastic snap
rivets provided.
7. 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 GC868 flowmeter may now be placed back into service. Reconnect the
main power and refer to Appendix C,
Optional Enclosures
, of the
Startup Guide
for
instructions on wiring the new option card(s).
Note:
Be sure to record the option card installation in Appendix A,
Service Record
.
B.5 Rack Mount
EPROM
Replacement
The Model GC868’s
User Program
is stored on an erasable programmable read only
memory (EPROM) chip. The EPROM, which is designated as component U4, is located
on the corner of the printed circuit board just behind the keypad on the front panel.
EPROM replacement may be required to replace a defective chip or to upgrade to a
newer software version. To replace the EPROM, refer to Figure B-2 on page B-9 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.
2. Using a chip puller, remove the EPROM from its socket. If a chip puller is unavail-
able, a straightened paper clip may be used in the notches at opposite corners
of the socket. Gently pry the EPROM up, a little at a time, at each notch until it
comes free.
3. Make sure that the beveled corner on the new EPROM is aligned with the beveled
corner of the socket and place the EPROM into the socket.
4. By applying equal pressure on all four corners, gently press the EPROM into the
socket until it is fully seated. Do not strike the EPROM or apply excessive force
during this procedure.
5. 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 GC868 flowmeter may now be placed back into service. Reconnect the
main power and resume taking measurements.
Note:
Be sure to record the EPROM replacement in Appendix A,
Service Record
.
WARNING! The main power to the Model GC868 must be
disconnected before proceeding.
CAUTION!
The EPROM is easily damaged by static electricity.
Before handling the new chip, touch a grounded metal
object to discharge any built-up static electricity and
avoid touching the leads on the side of the chip.