Miller Millermatic 350P Technical Manual page 53

Always perform pre-power troubleshooting before applying power to unit (see Section 8).
Trouble
Fan motor FM not operating properly.
Wire Drive/Gun Trouble
Electrode wire feeding stops during
welding and/or HELP 5 is displayed.
.
For troubleshooting and maintenance of XR - AlumaPro Gun, see TM-227398.
Millermatic 350
If gas flow is excessive, replace regulator.
Check coil voltage and connections of gas valve GS1. Check continuity of coil. Replace GS1 if necessary.
Check main control board PC1 and connections, and replace if necessary (see Section 9-5).
Check and clear blocked fan blade.
Check coil voltage and connections of fan motor FM, and replace if necessary.
Check for +24 VDC to fan motor from PC1, and replace PC1 if necessary.
Straighten gun cable and/or replace damaged parts (see gun Owner's Manual).
Adjust drive roll pressure (see Section 4-13, 4-14, or 4-15).
Readjust hub tension (see Section 4-8).
Replace contact tip if blocked (see gun Owner's Manual).
Clean or replace wire inlet guide or liner if dirty or plugged (see Section and gun Owner's Manual).
Check and clear any restrictions at drive assembly and liner (see Section and gun Owner's Manual).
Replace drive roll if worn or slipping (see Section 10-5).
Secure gun trigger plug in receptacle RC1 (see Section 4-3).
Check continuity of gun trigger and leads. Repair leads or replace trigger switch if necessary (see gun
Owner's Manual).
Check voltage and connections of wire drive motor PM. Check continuity of armature. Replace motor if
necessary.
Remedy
Remedy
TM-1327 Page 49