Troubleshooting and repair, Warning – Lincoln Electric POWER MIG SVM157-A User Manual
Page 51
TROUBLESHOOTING AND REPAIR
F-17
F-17
POWER MIG 200
WIRE DRIVE MOTOR AND TACHOMETER FEEDBACK TEST
(continued)
5. Make the following voltage tests:
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.
6. If the voltage to the wire drive motor arma-
ture is zero, check the wires between plug
J4 and the wire drive motor. Also check
the electrical connector J5 for proper con-
nections and jumper plug. See the Wiring
Diagram.
7. 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.
8. If the motor is running at high speed and
the armature voltage is high and uncon-
trollable, Proceed with the tachometer test.
TEST FOR SUPPLY VOLTAGE TO
TACHOMETER
1. Disconnect the main AC input power to the
machine.
2. Locate plug J4.
3. Locate the tach leads on plug J4. See
4. Connect the main input power to the
machine.
5. Make the following voltage tests:
a. Turn the machine OFF between each test.
b. Carefully insert the meter probes into the
lead side of plug J4.
6. If the 5-6 VDC is present, check the leads
to the tachometer circuit.
7. If the leads are okay and 5-6 VDC is pre-
sent, the correct voltage is being received
from the control PC board. Continue with
the supply voltage to tachometer test.
8. If the 5-6 VDC is not present and the leads
are okay, the control PC board may be
faulty, replace the control PC board. Also
check plug J5 and the jumper plug. See
Wiring Diagram.
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.
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.
WARNING
FROM LEAD
FROM LEAD
FROM LEAD
Black
Armature
Lead
White
Armature
Lead
2-29 VDC
(varies depend-
ing on wire feed
speed)
FROM LEAD
FROM LEAD
FROM LEAD
Black (-)
Red (+)
5-6 VDC