The first thing to say is that the Vision Monitors are extremely reliable and in the vast majority of cases a Monitor Fault is most likely an indication of another problem or a configuration issue.
My Monitor Displays a Blue Screen
A Blue screen indicates that the Monitor is working but is not receiving an image from the camera.
If the Monitor is connected to a DVR first check the DVR is working which you can check be making sure that a number of Green LEDs are illuminated one of which should be flashing. If the DVR is working there still could be a wiring or DVR fault however we have found in most instances the Monitor configuration has been changed.
On the M-515/715 Monitors the
Please follow link to this video to show you how to change these settings
Side Scan is Continuously turning off
Left Turn Alrm does not work