D)
Determine if sensor is still useful by following the calibration
procedure given sin Section VII.
E)
If fault is not corrected, return to MMC for repair. Sensor or
integrated circuit chip may require replacement.
PROBLEM NO. 5: Liquid Crystal Display (LCD) does not function properly one or more
segments stay on or off all the time producing strange figures.
PROCEDURE &
EXPLANATION:
Display contact may be corroded or dirty. Remove hub cover and
associated P.C. Board by first removing six machine screws. Remove the
three push-button switches and seal boot fasteners. P.C. Board and
associated display may now be separated from cover plate. Remove LCD
display bezel (see Dwg. B-2401-31) by first removing two machine
screws and nuts. Carefully lift bezel and liquid crystal display from blue
connector. Make sure that the long thin elastomer contact strips that fit
into the top and bottom horizonal slots of the connector are not lost.
Remove connector with associated contact strips exposing P.C. Boards
contacts. If corroded or dirty, wipe contact (bottom side only) with cotton
swab wet with alcohol, being careful not to saturate LCD with fluid.
CAUTION!
Do not spray contact cleaner on LCD display or permanent damage may
be incurred. Re-assemble in reverse order making sure elastomer contact
strips are inserted properly in blue connector horizontal slots. Note that
blue connector bottom pins fit into mating hose on P.C. Board for proper
alignment. If above procedure does not cure problem, then either display
or integrated circuit A/D converter is at fault. Spare display can be
substituted to isolate problem. Order from MMC together with new
connector.
PROBLEM NO. 6: Display is damaged, permanently discolored, broken.
PROCEDURE &
EXPLANATION:
Order new display and connector from MMC and follow procedure given
in Problem No. 5 to replace.
PROBLEM NO. 7: Unit operated properly in temperature mode, however, when placed in
ullage mode, horn does not sound in water, or sound is extremely weak.
PROCEDURE &
EXPLANATION:
Sonic sensor has probably been damaged by being dropped and
replacement may be required. Check unit in a container of clean lube oil,
and then in a container of water. If sensor does not respond per operating
procedure, then sensor replacement is probably necessary. Return to
factory.
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