Lincoln Electric PRECISION TIG 185 SVM169-A Service Manual page 45

F-7
TROUBLESHOOTING GUIDE
PROBLEMS
(SYMPTOMS)
Machine welds at a very low output
regardless of the current control set-
ting.
The machine welds at a very high
output regardless of the current con-
trol setting.
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
1-888-935-3877.
TROUBLESHOOTING & REPAIR
POSSIBLE AREAS OF
MISADJUSTMENT(S)
OUTPUT PROBLEMS
1. If welding in the TIG mode the
remote control device may be
defective.
2. Make certain the input line volt-
age is correct for the machine
reconnect configuration.
3. Check the welding cables and or
torch for loose or faulty connec-
tions.
1. If welding in the TIG mode the
remote control device may be
defective.
CAUTION
PRECISION TIG 185
Observe Safety Guidelines
detailed in the beginning of this manual.
RECOMMENDED
COURSE OF ACTION
1. Check the polarity switch and
associated leads.
2. Check the interior connections of
the heavy current carrying leads.
3. Perform the SCR Bridge Test.
4. Perform the T1 Transformer
Test.
5. Check the current control for
proper operation. Normal resis-
tance is 10k ohms. See wiring
diagram.
6. The control board may be faulty.
1. Perform the SCR Bridge Test.
2. Perform the T1 Transformer
Test.
3. Check the current control for
proper operation. Normal resis-
tance is 10k ohms. See wiring
diagram.
4. The control board may be faulty.
F-7