Hi Andy.
Thanks for posting again on the forum. Sorry to hear that you are still experiencing issues.
What is the product code of your ActivBoard?
Could you please confirm the driver version and firmware version in the ActivManager control panel.
How long is the USB cable and is this being plugged in to any wall boxes or connection plates?
If you would like to contact us directly for this issue, please quote your reference number which is 00419644.
I look forward to your response.
Adam
Promethean Technical Support