Miller VL-M4, Owner'S Manual, Page: 29 / 36

OM-189 530 Page 25
6-3. Troubleshooting Table
Trouble Remedy
Unit is completely inoperative. Check fuses F1 and F2, and replace if necessary (see Section 6-2).
No wire feed during inching. Place Power Switch S1 in On position (see Section 5-2).
Check 115 volts ac input power and be sure it is energized.
Check Fuses F1 and F2, and replace if necessary (see Section 6-2).
Run-In Speed Control set too low; increase Run-In Speed setting (see Section 5-3).
Check wire feed motor, and repair or replace if necessary.
Check switches S1, PB3, PB4, and PB5, and replace if necessary (see Section 5-2 and Parts List).
Check motor relay CR2 on Relay Board PC1, and replace CR2 if necessary (see Parts List).
Have Factory Authorized Service Agent check Relay Board PC1 and Motor Drive Board PC2, and
replace if necessary.
Wire feeds wrong direction during
inching. To change direction, reverse motor connections to terminals A and B on terminal strip TE2 if neces-
sary.
Wire only feeds down whether Inch
Down or Up button is pressed. Check motor direction relay CR4 on Relay Board PC1, and replace CR4 if necessary (see Parts
List).
No wire feed after Start button is Check Start switch PB2, and replace if necessary.
pressed (ensure that all wire feed
inching functions are operating prop-
Check weld latch relay CR5, and replace CR5 if necessary.
erly before checking this problem).
Check time delay relay CR6, and replace if necessary.
Check weld contactor relay CR3 on Relay Board PC1, and replace CR3 if necessary.
Check burnback time delay relay TD1, and replace TD1 if necessary (see Parts List).
No wire feed speed control with Wire Check Wire Speed control R5, and replace if necessary.
Speed control during welding, but
speed can be controlled with Run-In
speed control.
Check current sensing circuit in shunt box by checking for contact closure coming from shunt box to
pins G and H on 17-pin receptacle of weld control.
Have Factory Authorized Service Agent check motor board PC2, and replace if necessary.
No contactor control for welding power Check weld contactor relay CR3 on Relay Board PC1, and replace CR3 if necessary.
source (ensure that welding power
source is working properly and that all
connections are correct).
Check weld latch relay CR5, and replace if necessary.
connections are correct).
Check time delay relay CR6, and replace if necessary.
No output control for welding power
source. Check Output control R4, and replace if necessary.