Troubleshooting Guide - Lincoln Electric SQUARE WAVE SVM118-A Service Manual

F-5

TROUBLESHOOTING GUIDE

PROBLEMS
(SYMPTOMS)
The input contactor activates
when "start" button is pushed but
will NOT stay closed. Machine
shuts off when "start" button is
released.
The machine shuts off and the
control fuse (F1) 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)
OUTPUT PROBLEMS
1. Check the input voltage at the
machine. Input voltage must
match the rating plate and the
reconnect panel.
2. Blown or missing control cir-
cuit fuse (F1).
1. Check the input voltage at the
machine. Input voltage must
match the rating plate and the
reconnect panel.
2. Make sure the fuse is the cor-
rect rating (1/2 amp).
3. The input voltage may be too
high (more than 10% over
rated).
CAUTION
SQUARE WAVE TIG 355
Observe Safety Guidelines
detailed in the beginning of this manual.
RECOMMENDED
COURSE OF ACTION
1. Perform the Input Contactor
Test.
2. Perform the Control
Transformer Test.
3. Perform the Feed – Thru PC
Board Test.
4. Perform the Control Board
Interlock Test.
5. The power board may be
faulty. Replace.
1. Perform the Control
Transformer Test.
2. Perform the Power Board
Test.
3. The control board may be
faulty. Replace.
F-5