Troubleshooting & repair, Caution – Lincoln Electric LN-9 SVM127-A User Manual
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TROUBLESHOOTING & REPAIR
F-9
F-9
LN-9 Wire Feeder
TROUBLESHOOTING GUIDE
Observe Safety Guidelines
detailed in the beginning of this manual.
CAUTION
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con-
tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call
216-383-2531 or 1-800-833-9353.
PROBLEMS
(SYMPTOMS)
POSSIBLE AREAS OF
MISADJUSTMENT(S)
RECOMMENDED
COURSE OF ACTION
FUNCTION PROBLEMS
The SET speed is erratic or not
adjustable over entire range of con-
trol. The actual speed is also errat-
ic like the SET speed.
1. Check for loose or faulty con-
nections on leads #631, #632,
and #633 between the speed
control potentiometer (R2) and
the control PC board.
1. Remove power to the LN-9 and
disconnect the plug to the con-
trol PC board. Check the resis-
tance of the speed control
potentiometer (R2). When mea-
sured from the wiper (lead
#632) to lead #633, the resis-
tance should vary smoothly
from 0 to 10,000 ohms, when
the shaft is rotated. See the
Wiring Diagram.
2. The control PC board may be
faulty. Replace.
The wire continues to feed with the
gun trigger open, and the wire is
electrically "hot." The interlock
switch is in the "OFF" position.
1. Disconnect the gun trigger cable.
If the problem is resolved, the
gun trigger or cable is faulty.
Repair or replace.
1. Disconnect lead #530 from the
trigger board. See the Wiring
Diagram. If the problem is
resolved, the trigger board is
faulty. Replace.
2.
Relay 1CR may be stuck
closed. Check or replace.
3. The power PC board may be
faulty. Replace.