Lincoln Electric WIRE-MATIC 255 SVM 119-A Service Manual page 57

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TROUBLESHOOTING GUIDE - Observe all Safety Guidelines detailed throughout this manual
PROBLEMS
(SYMPTOMS)
No control of arc voltage. Wire feed-
ing is normal.
There is no gas flow when gun trig-
ger is pulled. Wire feeds and weld
voltage is present.
The machine stops feeding wire
while welding.
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, con-
tact the Lincoln Electric Service Department for technical troubleshooting assistance before you proceed call 216-
383-2531 or 1-800-833-9353
TROUBLESHOOTING & REPAIR
POSSIBLE AREAS OF
MISADJUSTMENTS(S)
FUNCTION PROBLEMS
1. The Arc Voltage Control poten-
tiometer may be dirty.
several times and check if prob-
lem is resolved.
1. Check gas source and hoses for
leaks or kinks.
2. If Spool Gun adaptor is not
installed make certain jumper
plug is installed in plug J20. See
Wiring Diagram.
1. Check for mechanical restric-
tions in the wire feeding path.
The gun may be clogged.
CAUTION
WIRE-MATIC 255
RECOMMENDED
COURSE OF ACTION
1. The Arc Voltage Control poten-
Rotate tiometer may be faulty. Check or
replace. See Wiring Diagram.
2. Perform the SCR Rectifier
Assembly Test .
3. The control board may be faulty.
Replace.
1. Check the gas solenoid by dis-
connecting it from the control
board (Plug J8) and applying a
12 VDC external supply to the
gas solenoid.
does NOT activate then it may
be faulty. Replace.
2. The control broad may be faulty.
Replace.
1. Check the motor armature cur-
rent. Normal armature current is
1.75 amps maximum.
motor armature current is normal
the control board may be faulty.
Replace.
2. If the motor armature current is
high (2 to 2.5 amps) and there
are NO restrictions in the wire
feeding path then the motor or
gear box may be defective.
Replace.
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If the solenoid
If the