How do I test if my KSM150 is in good working condition before attempting repairs?

A wattmeter test should be made by setting the wattmeter to the proper voltage, plugging the mixer cord into the wattmeter, and running the mixer. If the wattmeter shows up to 135 watts going from stir to #10 speed, the mixer is in good condition. If the reading is 175 to 400 watts, there is a problem indicating either electrical or mechanical issues.