Lincoln Electric POWER MIG SVM167-A Service Manual page 52

F-16
TROUBLESHOOTING AND REPAIR
WIRE DRIVE MOTOR AND WIRE SPEED POTENTIOMETER TEST
1. Make the following voltage tests:
WARNING
ELECTRIC SHOCK can kill.
• Do not touch electrically live
parts such as output terminals
or internal wiring.
• All input power must be electri-
cally disconnected before pro-
ceeding.
a. Turn the machine OFF between each test.
b. Carefully insert the meter probes into the lead side
of plug J4. See Figure F.4.
c. Turn the machine ON and pull the gun trigger to
conduct the voltage test.
FROM LEAD
FROM LEAD
Black
White
Armature
Armature
Lead
Lead
2. If the voltage to the wire drive motor armature is
zero, check the wires between plug J4 and the wire
drive motor. Also check the electrical connector J5
for proper connections and jumper plug. See the
Wiring Diagram.
3. If all wires and connectors are good and the voltage
to the drive motor armature is zero, the control PC
board may be faulty. Replace the control PC board.
4. If the motor is running at high speed and the arma-
ture voltage is high and uncontrollable, replace the
control board.
(continued)
FROM LEAD
2-29 VDC
(varies depend-
ing on wire feed
speed)
POWER MIG® 215
Figure F.4 - Plug J4
Black Black
White
Tach Arm
J11 J11
Blue
Red
Tach
Tach
F-16
Arm