All-in-one cable or logic board problem?

Hi! When I connect the USB portion of my monitor's all-in-one cable to any computer (well, either my macbook air or my mac mini), it says that the USB port is drawing too much power and that I need to disconnect it. This leaves my monitor non-functional in some respects, such as the speakers will not play sound, and I cannot use the ports on the back of the monitor.

Is it possible that I could repair this just be replacing the all-in-one cable? Or might the logic board somehow have been fried?

Everything else about the monitor seems to work just fine--the picture is great, and the power cord still charges my macbook air. FYI - I have not had anything plugged into the USB ports on the back of the monitor when this problem has occurred.

Thanks in advance!