Lincoln Electric SVM138-A Service Manual page 74

F-10
Observe Safety Guidelines
detailed in the beginning of this manual.
PROBLEMS
(SYMPTOMS)
The wire feeds when the interlock
switch is in the "ON" position. No
welding or gun trigger activation.
With the interlock switch in the
"ON" position, the wire feed stops
when the gun trigger is released.
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.
TROUBLESHOOTING & REPAIR
POSSIBLE AREAS OF
MISADJUSTMENT(S)
TRIGGER INTERLOCK FUNCTION PROBLEMS
1. Check to see if the reed switch
2CR is stuck closed.
1. Check leads #529 and #628 for
loose or faulty connections
between the 2CR reed switch
and the power PC board.
CAUTION
LN-9 GMA Wire Feeder
TROUBLESHOOTING GUIDE
RECOMMENDED
COURSE OF ACTION
1. Check the 2CR reed switch for
sticking and associated leads
(#529 and #628) for shorts.
2. The power PC board may be
faulty. Replace.
1. The 2CR reed switch may be
faulty. Check to see if it closes
when welding.
2. Check the continuity (zero
ohms) of leads #529 and #628
from the 2CR reed switch to the
power PC board. Also check
continuity of leads #530 and
#522 from the power PC board
to the interlock switch. See the
Wiring Diagram.
3. Check the interlock switch for
proper operation.
4. The power PC board may be
faulty. Replace.
F-10