Troubleshooting Table - Miller Millermatic 140 Auto-Set Owner's Manual

6-5. Troubleshooting Table

Trouble
No weld output; wire does not feed; fan
does not run.
No weld output; wire does not feed; fan
motor continues to run.
No weld output; wire feeds.
Low weld output.
Electrode wire feeding stops during
welding.
OM-225 311 Page 32
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A complete Parts List is available on-line at www.MillerWelds.com
Secure power cord plug in receptacle (see Section 4-8 or 4-9).
Replace building line fuse or reset circuit breaker if open.
Place Power switch in On position (see Section 5-1 or 5-2).
Reset welding power source supplementary protector if open.
Thermostat TP1 open (overheating). Allow fan to run with gun trigger switch off; thermostat closes when
unit has cooled (see Section 5-1 or 5-2).
Secure gun trigger plug (see Section 4-1).
Release gun trigger and cycle unit power off and back on again.
Connect work clamp to get good metal to metal contact.
Check for loose connections.
Replace gun contact tip (see gun Owner's Manual).
Check for proper polarity connections (see Section 4-5).
Check thumbscrew securing gun end to feed head adapter and tighten if necessary.
Connect unit to proper input voltage or check for low line voltage.
Place Power switch in On position (see Section 5-1 or 5-2).
Straighten gun cable and/or replace damaged parts.
Adjust drive roll pressure (see Section 4-12).
Change to proper drive roll groove (see Section 6-4).
Readjust hub tension (see Section 4-11).
Be sure that wire is positioned in proper drive roll groove and wire is laying in the groove.
Replace contact tip if blocked (see gun Owner's Manual). Oversized tip may be required for some wires.
Clean or replace wire inlet guide or liner if dirty or plugged (see Section 6-4 or gun Owner's Manual).
Replace drive roll or pressure bearing if worn or slipping (see Section 6-4).
Secure gun trigger plug (see Section 4-1).
Check and clear any restrictions at drive assembly and liner (see Section 6-4 or gun Owner's Manual).
Release gun trigger and allow gun and motor protection circuitry to reset.
Have nearest Factory Authorized Service Agent check drive motor.
Remedy