Lincoln Electric SVM138-A Service Manual page 77

F-13
TROUBLESHOOTING GUIDE
PROBLEMS
(SYMPTOMS)
The 1/8 amp fuse on the voltage
PC board repeatedly fails.
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 to make sure the PC
boards are NOT grounded to
the case of the LN-9 GMA.
This can happen due to metal-
lic wire shavings build-up.
CAUTION
LN-9 GMA Wire Feeder
Observe Safety Guidelines
detailed in the beginning of this manual.
RECOMMENDED
COURSE OF ACTION
1. Remove input power to the LN-
9 GMA. Replace the 1/8 amp
fuse and switch the LN-9 GMA
polarity switch to the "NEG"
position.
Make a resistance check from
the following leads to the LN-9
GMA case grounding screw:
Leads # 500, 510, 525, 522,
526, 530, and 628.
The resistances should be
above 1000 ohms. If any test
is below 1000 ohms, that circuit
has low resistance to case
ground. Isolate the faulty leads
or PC board. See the Wiring
Diagram and Schematic.
F-13