When I first plug in a new Suni digital x-ray system, you can only capture images intermittently.
The Suni hardware has an internal battery that it uses to supplement its power during x-ray acquisition. This battery is automatically charged by the system when the hardware is plugged into a computer via a USB cable (the USB cable supplies power to the hardware). When you first plug in the Suni hardware, its internal battery could be weak enough where it cannot supply enough power for the hardware to complete taking an image.
Wait 1 or 2 hours after plugging in the new Suni hardware before trying to capture an image.