If you are holding a light bulb that no longer works because the filament is broken you could say: This light bulb is burned out. This light bulb is blown out.

How do you tell when a light bulb is burned out?

The trick is to shake the bulb lightly once the bulb has cooled off completely. If you hear something rattling around, the filament has broken, and you know the bulb has burnt out or is otherwise damaged. Low wattage bulbs may produce a very unpleasant smell if they have burnt out.

What is a burned out light bulb?

There are many possible reasons why a light bulb burns out quickly: The power supply voltage may be too high. Bulbs may be loose or connected improperly. Excessive vibrations may be causing the filament to break.