Paul,
Since cycling the power seems to help for a while, try swapping one of the boards power supply with a working a board and see if that helps. The board's serial number you provided is still under warranty. Please contact Technical Support via the web form on the knowledge base at www.prometheankb.com, select your region/language, Interactive Displays, Contact Us. In the Existing case field input case number: 237495 and provide the serial number for all 3 boards that you are having issues with.
Thanks!
