Possible Cause
Defective wire feed motor or wire drive
control 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.
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 procedure on page
19).
Replace PCB. (Refer PCB replacement
procedure on page 19).
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
circuit.
Replace defective contactor
Set controls correctly.
Replace switch.
Replace.
Replace.
Replace
Replace.
Check fuses, check input connection.
Problem
No wire feed, although arc
voltage 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.
TROUBLESHOOTING
Page 22
REDI-MIG 325
IMA 599B
