Lincoln Electric 11519 Service Manual page 53

F-7
Observe Safety Guidelines detailed in the beginning of this manual.
PROBLEMS
(SYMPTOMS)
No control of arc voltage. Wire
feeding 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,
contact the Lincoln Electric Service Department for technical troubleshooting assistance before you proceed.
Call 1-888-935-3877.
TROUBLESHOOTING AND REPAIR
POSSIBLE AREAS OF
MISADJUSTMENT(S)
FUNCTION PROBLEMS
1. The arc voltage control poten-
tiometer may be dirty. Rotate
several times and check if prob-
lem is resolved.
1. Check gas source and hoses for
leaks or kinks.
1. Check for adequate wire supply.
2. Check for mechanical restric-
tions in the wire feeding path.
The gun may be clogged.
3. Check gun liner and tip are cor-
rect for wire size being used.
4. Check spindle for ease of rota-
tion.
5. If Timer Option Kit is installed,
make sure spot timer knob is set
to OFF.
CAUTION
Power MIG® 255XT
RECOMMENDED
COURSE OF ACTION
1. The arc voltage control poten-
tiometer may be faulty. Check
or replace. See
Diagram.
2. Perform the SCR Rectifier
Assembly Tests.
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. If the 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 2.0 to 2.7 amps maximum. If
the motor armature current is
normal the control board may
be faulty. Replace.
2. If the motor armature current is
high (over 2.7 amps) and there
are NO restrictions in the wire
feeding path then the motor or
gear box may be defective.
Replace.
F-7
Wiring