How to Tell If a Projector Bulb Is Bad

You can tell if a projector bulb is bad with a multimeter.

To tell if a projector bulb is dead, you must check for electrical continuity throughout the light bulb circuit through the base of the bulb. The best way to do this is to use a multimeter set to the ohms position. However, there are many different and varying styles of projector bulb bases. Some have the classic screw-in base, some have a couple of electrical prongs protruding from the base, and some will have just a couple of electrical contacts, yet they all get tested in essentially the same way.

Things You'll Need

• Multimeter

Instructions

1. Set the multimeter to the ohms position. Most have a frontal dial that can be turned to access this function, but some will have different positioning holes on the front where the probes must be inserted into to access the ohms function.

2. Touch one multimeter probe to a tab or prong on the base of a projector bulb. If it is a classic screw-in bulb, touch a probe directly to the tip of the base.

3. Touch the other multimeter probe to the other tab or the prong on the base. If this is a screw-in type of bulb, touch the second probe to the metallic side of the bulb.

4. Read the multimeter. If the multimeter reads "0" or "infinity," the bulb is bad and will need to be replaced. Any other reading other than "0" means that there is resistance through the filament, and the bulb is good.

References

• Ohm Check: How To Test A Light Bulb
• @ Year Net: How To Test An Old Lightbulb For Continuity

Resources

• Buy Lighting: Projector Bulbs