Lincoln Electric IM539 Synergic 7F and 7FH - Manual (Page 33)

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PROBLEM
14. Cold Feed key does not turn
on wire feed motor but trigger
closure does.
15. Display and/or indicator lights
do not change when the arrow
or select keys are pressed.
16. Display does not change when
WFS and/or Volts/Trim knobs
are turned.
17. Display is blank.
POSSIBLE CAUSE
a. Defective keypad or Display PC
board is defective.
\a. Defective keypad or Display PC
board.
a. Make sure that the function
select key has been pressed to
light the LED corresponding to
the Volts/Trim or WFS display
depending on which knob you
are attempting to adjust.
b. Broken harness wire(s) or
harness disconnected from
encoder boards(s) or control
board.
c. Defective Encoder boards and/or
control board.
a. Power source is OFF.
b. Feeder supply fuse or circuit
breaker at power source is blown
or tripped.
c. Display or Control PC board is
bad.
WHAT TO DO
a. Check continuity between sockets 4
and 1 of keypad connector when
Cold Feed key is closed. If not,
then replace keypad, otherwise,
replace Display PC board. (See
Procedure for Replacing PC
boards).
a. Ring out keypad. Replace if
defective. If not, then replace
Display PC board. (See Procedure
for Replacing PC boards.)
a. Press the function key to light the
LED next to the display function that
corresponds with the knob to be
adjusted.
b. Check harness connections to
encoder and control boards and
continuity between corresponding
harness leads in P2 and P17.
(Refer to wiring diagram).
c. If b. is not the problem and neither
the WFS or Volts/Trim knobs are
properly adjusting then replace the
control board. If one of the two
knobs are properly adjusting, plug
the P17 harness from the working
board into the nonfunctional board.
If the previously nonfunctional board
is now working, replace the control
board. Otherwise replace the
nonfunctional encoder board. (See
procedure for replacing PC boards).
a. Turn ON power source.
b. Check input cable and feeder unit
for short in 41 and 42 circuit. Check
for shorted motor. Replace fuse or
reset circuit breaker.
c. Observe LED mounted on Control
PC board. It should blink on and off
at a controlled rate of 1 second ON
and 1 second OFF. If so, then
replace Display PC board. If not,
replace Control PC board. (See
Procedure for Replacing PC
boards.)
PROBLEMS