Lincoln Electric REDI-MIG 4S Operator's Manual page 22

Problem
No wire feed, although arc volt-
age is present.
No control of wire feed.
No wire feed and no arc voltage.
Pilot light indicates input power
to machine.
Poor welding characteristics
and/or cannot obtain full rated
output as per nameplate.
Page 22
TROUBLESHOOTING
Possible Cause
Defective wire feed motor or wire drive con-
trol PC board.
Defective wire drive control PC board.
Overtemperature protection circuit actuated
due to overload or short. (Overtemperature
light should be illuminated).
Faulty gun trigger switch or damaged control
cable connected to gun trigger.
Defective control PC board.
Defective contactor
Improper settings for wire feed speed and
volts.
Faulty switch either coarse control (on/off) or
fine control.
Faulty pilot transformer.
Faulty main transformer.
Faulty rectifier.
Faulty choke.
One phase disconnected.
REDI-MIG 4S Wire Feeder
®
What To Do
Measure the voltage between the motor leads
(54) and (53) when the Gas Purge/Wire Inch
toggle switch is pressed downwards. If this
voltage is over 10V DC, replace the wire feed
motor. If no voltage is registered, replace the
wire drive PCB. (Refer PCB replacement pro-
cedure on page 19).
Replace PCB. (Refer PCB replacement pro-
cedure on page 20).
Allow machine to cool down and reduce on
time and/or wire feed speed.
Repair.
Refer Procedure for Replacing PC Boards, if
no fault is detected in trigger-thermostat cir-
cuit.
Replace defective contactor
Set controls correctly.
Replace switch.
Replace.
Replace.
Replace
Replace.
Check fuses, check input connection.
IM6020