The Miller Roughneck Welder is an engine-driven generator that is most commonly used as a welding generator. It can also be utilized as a 115-volt power source. However, it can not be simultaneously used for both purposes. The most common problems with the Miller Roughneck Welder are generator and engine problems.

No Welding Output

Make sure the Weld/Power switch S1 is in the "Weld" position if the machine is not producing welding output. If there is still no output, check the "Weld/Power" switch S1 connectivity. It may need to be replaced.

No Power Output

Make sure the Weld/Power switch S1 is in the "Power" position if the machine is not producing a power output. If the switch is in the "Weld" position, the machine will not produce a power output.

Low Weld Output

Check to see that the engine is running at 3,600 rpm if the machine is producing low weld output and the switch S1 is in the "Weld" position. If the engine is not at 3,600 rpm, the nuts on the Power Speed adjustment may need to be rotated.

Low Power Output

Check that the engine is running at 1,950 rpm or 1,600rpm, depending on your model number. If the switch S1 is in the "Power" position, and the engine is not running at these numbers, the engine may need servicing.

Power and Weld Output

Check the collector rings for excessive dirt if both the weld and power output are low or nonexistent. Clean the collector rings with 3/0 sand paper if necessary.