Lighting Troubleshooter

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Lighting Troubleshooter

Working with lights presents you with a number of challenges. And sometimes the answers aren't immediately obvious.

Take extra care when working with mains powered lights. Tungsten, halogen and HMI lights get very hot. Always wear protective gloves when handling them.

Light receiving power, but not working

You're sure power is getting to the light, but it's not coming on.


  1. There might be another power switch on the light cable or on the power unit for the light.
  2. Check if there’s a dimmer control on the power unit or the head unit. It could be on its lowest setting.
  3. If the light has a fuse in the back of the head unit, try changing it.
  4. If the light has a removable lamp or tube, try reseating it. If that doesn’t work, replace it. You know a lamp has blown if there are soot marks on the glass, or the filament is visibly broken or melted. A fluorescent tube has blown if it rattles when you shake it.
  5. If the light’s connected to a DMX desk, check the settings on the desk. Also check the data cables haven’t worked loose.

Specifically for HMI lights:

Take care with the HMI ballast, it retains a charge even when the power is disconnected.

  • An HMI light might have a switch on the ballast for different voltages, check it’s set correctly.
  • If you switch off an HMI light, you might need to wait a few minutes before it will power on again.
  • The lamp might not work without the UV protector in place. This should not be removed as it provides extra protection for your eyes.

Light is smoking

Smoke is coming out of a hot light.


A smoking light can be caused by dust, paint or grease heating up.

Switch off the light and allow it to cool. Open the bulb access and check for material that could create smoke.

Folding pop-up reflector

I can't fold the pop-up reflector to get it back in its bag.


This is every filmmaker’s rite of passage… embrace it!

Okay, okay! I’ll give you a hint…

Hold the reflector in front of you with both hands. Twist the edges in opposite directions.