How to Troubleshoot a Stage Dimmer

Stage lighting involves many steps between the control channel on your lighting console that raises and lowers the level and the lighting instrument itself. What appears as dimmer failure may be caused by a breakdown in communication at any step along the way. Start at the light, as this is where most common troubles occur, and work your way backward to the lighting console. Many people confuse dimmers with circuits in stage lighting. The circuit is the outlet and cabling into which you plug the light. The dimmer is the unit that controls how much power flows through that circuit. The control channel is what tells the dimmer how much power to release.

If Only One Dimmer Doesn't Work

• 1

  Unplug your lighting instrument from the circuit you are having trouble with and plug in a different light, preferably one that you know works. Bring up the channel on your console that corresponds with the dimmer and circuit. If the light comes on, the problem is with your lighting instrument, not the dimmer. Most likely you simply need to replace the lamp.

• 2

  Check to make sure your dimmer and channel are connected to each other if the second light also doesn't work. Many modern theaters have these permanently connected and you can skip this step, but some theaters have a more flexible system. Ask the theater technical director (TD) or electrician if the theater is on a "Dimmer per circuit" system, meaning they are permanently assigned. If so, try the next step. If not, ask the electrician or TD to show you how to assign a dimmer to a circuit. This process varies widely by theater and should always be supervised by the theater staff.

• 3

  Find a button marked "Patch" on the lighting console or ask a theater employee how to check the patch. The patch is a software command in the lighting console that tells the equipment which control channel is assigned to which dimmer. In the patch display on the console, locate the channel number you are using to control the light. Make sure the number representing the circuit or dimmer (depending on the theater's labeling system) where the light is plugged in is displayed next to the appropriate channel.

• 4

  Correct the patch if the dimmer and channel are not assigned. On most modern boards, this is done in the "Patch" screen by pressing "Dim" or "Dimmer," then the dimmer number and "Enter," then "Chan" or "Channel" and the control channel number, then "Enter."

• 5

  Turn on the light again. If it still does not come on, call the staff electrician or technical director. They may have a malfunctioning dimmer pack or broken control channel, both of which require licensed repair technicians.

If No Dimmers Work

• 1

  Turn the lighting console off and wait about 20 seconds, then turn it back on again. Occasionally a software malfunction can cause issues with the connection between the control channels and the dimmers.

• 2

  Locate a slider or switch on the lighting console and make sure it is in the "On" or "100 percent" position. Try turning on lights again.

• 3

  Look at the cables on the lights to make sure you have lights plugged into the dimmers you are trying to control. If this is the issue, plug in the lights and try turning them on again.

• 4

  Check the dimmer racks to make sure they are receiving power. Dimmer configuration varies greatly, but if you do not see lights and hear fans when inside the dimmer room, the dimmers are not on. Contact the theater's staff to turn them on for you. While uncommon, a blown circuit leading to the dimmer racks can cause failure of all dimmers. Also, some theaters turn off the dimmer racks when the stage is not in use for a long period of time.