Miller S-74 MPa Plus Technical Manual

TM-273245 Page 31S-74 MPa Plus
Trouble Remedy
Clear blockage in gas hose or replace hose.
Check coil voltage and connections of gas valve GS1. Check continuity of coil. Replace GS1 if necessary.
Check trigger filter board PC8 and connections, and replace if necessary (see Section 9-11).
Check motor board PC1 and connections, and replace if necessary (see Section 9-4).
Shielding gas flow is irregular, but wire
feeds and electrode wire is energized.
Check coil voltage and connections of gas valve GS1. Check continuity of coil. Replace GS1 if necessary.
Clean filter screen in valve.
Clear blockage in gas hose or replace hose.
Clear blockage in welding gun. See gun Owner’s Manual.
Welding arc is too cold regardless of
voltage control preset.
Check extension cord and 14 pin plug connections. If secure, check cord for continuity and repair or
replace if necessary.
Check motor board PC1 and connections, and replace if necessary (see Section 9-4).
Check 14-pin filter board and connections, and replace if necessary (see Section 9-10).
Welding arc is too hot regardless of volt-
age control preset; power source works
with it’s panel setting.
Check extension cord and 14-pin plug connections. If secure, check cord for continuity and repair or
replace if necessary.
Check motor board PC1 and connections, and replace if necessary (see Section 9-4).
Check 14-pin filter board and connections, and replace if necessary (see Section 9-10).

Miller S-74 MPa Plus Specifications

General

Brand	Miller
Model	S-74 MPa Plus
Category	Wire Feeders
Language	English