Troubleshooting - Miller Maxstar 200 STR Owner's Manual

6-4. Troubleshooting

Trouble
No weld output; unit completely
inoperative.
No weld output; Output LED on.
No weld output; Overtemp LED on.
Erratic or improper weld output.
Fan not operating.
Wandering arc
Tungsten electrode oxidizing and not re-
maining bright after conclusion of weld.
OM-2233 Page 30
Place line disconnect switch in On position (see Section 4-12).
Check and replace line fuse(s), if necessary, or reset circuit breaker (see Section 4-12).
Check for proper input power connections (see Section 4-12).
Input voltage outside acceptable range of variation (see Section 4-11).
See Section 6-3, Troubleshooting Help Aids.
Unit overheated. Allow unit to cool with fan On (see Sections 4-5 and 6-3).
Use proper size and type of weld cable (see Section 4-7).
Clean and tighten all weld connections (see Section 4-7).
Check for and remove anything blocking fan movement.
Have Factory Authorized Service Agent check fan motor.
Use proper size tungsten (see Section 8).
Use properly prepared tungsten (see Section 8).
Reduce gas flow rate (see Section 4-9).
Shield weld zone from drafts.
Allow adequate postflow time to shield tungsten while it cools, after welding stops.
Check and tighten all gas fittings (see Section 4-9).
Water in torch. Refer to torch manual.
Remedy