Lumina Response pad Red Button always on

We have a problem with one of our response pads LU444-RH.
When we start the box it indicates that no buttons are being pressed.

But if we press the red button (4) it will indicate that its pressed but it will remain on until we Power the unit off. We tried to switch response pads to another main unit and we get the same error on the other unit so it seems that the problem is att the response pad.

Does anyone have any idea why this is happening.

Best Regards
Bjِrn Broo CMIV

This might be a defective unit. I will contact you via private message to assist you.