Fix the problem before it causes damage to your lights or electrical system.
Flickering lights. This is the most common sign of a bad ballast. The lights may flicker rapidly or slowly, and the flickering may be intermittent or constant.
Buzzing noise. A bad ballast can also make a buzzing or humming noise. The noise may be loud or faint, and it may be constant or intermittent.
Delayed start. When you turn on the lights, they may take a few seconds to start up. This is a sign that the ballast is not providing enough power to the bulbs.
Low output. The lights may be dimmer than usual or may not produce as much light as they used to. This is a sign that the ballast is not providing enough power to the bulbs.
Inconsistent lighting levels.The lights may be brighter in some areas and dimmer in others. This is a sign that the ballast is not distributing power evenly to the bulbs.