Rack Mount Eprom Replacement - GE DigitalFlow DF868 Service Manual

Appendix B. Optional Enclosures
B.5 Rack Mount EPROM Replacement
The Model DF868's User Program is stored on an erasable programmable read only memory (EPROM) chip. The
EPROM, which is designated as component
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 11 on page 50 and complete the following steps:
WARNING! The main power to the Model DF868 must be disconnected before proceeding.
1. After disconnecting the main power to the meter, remove the top panel from the enclosure by removing the four
screws indicated.
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.
2. Using a chip puller, remove the EPROM from its socket. If a chip puller is unavailable, 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 DF868 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.
44
U4
, is located on the corner of the printed circuit board just behind the
DigitalFlow™ Multipurpose Ultrasonic Liquid Flowmeter Service Manual