Lynn,
It seems that your board may be spiking. Other causes of spiking can be cabling, you may want to swap the USB cable and power supply and see if that resolves. If your board has embedded speakers in the frame, try either turning off the amplifier or unplugging it and powering the board USB only to see if the spiking persists.
If the above does not help a firmware update may resolve this issue. 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 224036. Please also provide the serial number of the board and the current firmware version listed in ActivManager, also please provide the troubleshooting steps you have tried so we may better assist.
Thanks!!