The ActivBoard may beep regularly while switched on. The LED in the top left corner may flash intermittently, accompanied by a clicking noise.
If this is happening, please try resetting the ActivBoard.
If the problem persists, try using a power supply from another ActivBoard. If another power supply solves the problem, then please contact your local Promethean reseller to purchase a replacement. If your system is under a year old we may be able to replace the power supply under warranty.
If the problem still occurs then please contact Promethean Technical Customer Support with your ActivBoard serial number so we can investigate further.