How do I test a ballast with a multimeter?
To measure it, set your digital multimeter to around a thousand ohms resistance setting. Connect the black leads to the white ground wire on your ballast. Afterward, test every other wire with the red lead. When you do this test, a good ballast will return an “open-loop” or max resistance.
What should you use to check the voltage in the ballast?
Test the ballast’s voltage with a multimeter. Attach the multimeter’s leads to the sockets at the ends of the ballast. If the reading is not between five and nine volts, replace the ballast. Adjust the multimeter to measure frequency and replace the ballast if the reading is not between 20 and 50 kilohertz.
How can you tell if a fluorescent light bulb is bad?

Look for dark areas at the base of the bulb. When bulbs age and have been used for a long time, brown spots will appear. If darkness begins to form at the ends of the tube, the bulb may be near its end. While they may still light, they are wearing out and will die soon.
Can a bad ballast burn out bulbs?
The ballast itself can go bad, which causes lights to flicker or even appear to be burnt out, when in fact they aren’t. They require maintenance and energy to power, on top of the power used to light the fluorescent bulb. They are a large part of the equation when using fluorescent lamps.
How do you check a ballast if it works?
One probe of the multimeter should touch the hot wire connections, while the other touches the neutral wire connections. If the ballast is good, an analog multimeter has a needle that will sweep to the right across the measuring scale. If the ballast is bad, then the needle won’t move.

Why do my fluorescent lights not turn on?
The fluorescent tube won’t turn on No electrical power due to a tripped breaker or blown fuse. A dead or dying ballast. A dead starter. A dead bulb.
Is there a way to test a fluorescent bulb?
Set a multimeter to the ohm (Omega symbol) setting, then touch one tester probe to each of the pins at the end of the bulb. If the tester shows a reading between 0.5 and 1.2 ohms, the bulb has continuity. Repeat the test at the other end of the bulb.