Note: While this guide is written with Promethean projectors in mind, other projector brands may have similar settings. The computer suggestions listed here should be applicable regardless of the brand or model of projector in use.

If a blue screen with 'No signal' is projected on your ActivBoard instead of your computer image, please check the following: 

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Connections and/or Wallbox

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  1. Check the connections at the back of the computer and projector and make sure they are secure. (Make a note of the projector input being used: Computer 1 or Computer 2).
  2. Check all connections to ensure they are secure, especially any wallboxes/extension cables.
  3. If you are using a wallbox attached to an ActivBoard+2 System, look along the underside of the box and determine which VGA port is in use. Ensure that the switch/buttons on the side are set accordingly.

Check the input

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  1. Verify which input on the projector the computer is plugged into.
  2. Press the MENU button on the remote control.
  3. Use the arrows to indicate the appropriate option, and press the Select button on the remote control.
  4. If connected to Computer 1, select RGB, not Component or RGB SCART.

Check your computer’s display settings

Note: For support for specific graphics cards and graphics drivers, you may need to consult your graphics card user manual, or the manufacturer’s website for assistance. The following are generally widely applicable suggestions:

For a PC laptop, it may be necessary to toggle a setting in order for the computer to generate an outgoing video signal. On most laptops, this is a key combination of Fn+F#, F# will usually have a picture of a monitor or the letters CRT/LCD. This setting should also be accessible through the graphics driver properties.

If you are using a Mac, it may be necessary to open System Preferences, go into the Arrangement tab, and click on Detect Displays.


  1. Attempt to connect another laptop to the projector. If this works then the issue is in the laptop’s settings or hardware.
  2. Attempt to connect using a direct connection with a known good VGA cable. If this allows the display to work correctly, then the issue is with a wallbox or piece of cabling.
  3. If neither of the above reveal the issue, connect the computer with known good cabling to another projector.
  4. If the issue is isolated to any piece or Promethean equipment (projector, wallbox), contact tech support for further assistance.