GE DigitalFlow DF968, Service Manual

Page: 66 / 78

Optional Enclosures B-5
March 2008
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
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-11 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 .