Lincoln Electric SVM138-A Service Manual page 76

F-12
TROUBLESHOOTING GUIDE
PROBLEMS
(SYMPTOMS)
Circuit breaker (3 amp) repeatedly
trips when the gun trigger is acti-
vated.
Circuit breaker (3 amp) trips when
power is applied to the LN-9 GMA.
Gun trigger is NOT activated.
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)
FUNCTION PROBLEMS
1. Check or replace gun trigger
and leads. Make sure the trig-
ger leads are not shorted to the
electrode or work cables.
1. Disconnect any kits that may be
incorporated in the LN-9 GMA
(K418, K419, etc.). Be sure to
install any necessary jumper
plugs. If the problem is re-
solved, the fault may be in the
disconnected kit.
CAUTION
LN-9 GMA Wire Feeder
Observe Safety Guidelines
detailed in the beginning of this manual.
RECOMMENDED
COURSE OF ACTION
1. Disconnect lead #500 from the
trigger PC board. If the breaker
still trips when the gun trigger is
activated, the trigger PC board
may be faulty. Replace
2. Disconnect any accessory that
may be connected to terminals
#7 and #32A. See the Wiring
Diagram. If the problem is
resolved, the accessory may be
faulty. Replace.
3. Perform the Wire Drive Motor
Test.
4. The power PC board may be
faulty. Replace.
1. Disconnect lead #620 from the
trigger PC board.
Wiring Diagram. If the problem
is resolved, the trigger PC
board may be faulty. Replace.
2. Perform the T2 Transformer
Test.
3. Check the harness leads #32A,
#31, and #531 for shorts or
grounds. See the Wiring
Diagram.
4. The power PC board may be
faulty. Replace.
F-12
See the