1.POS cash register displays a black screen
A and if there is no power supply. Check the chassis power connector and power cord power on, check the mainframe power interface and power cables are loose, and the monitor is opened, if the fracture of interface and the power cord is damaged it should be replaced in a timely manner to confirm if the power supply fan exhaust.
B, monitors the power and data cables are connected; changing to another computer for proper display on the monitor.
C, the monitor data cable for breakage or deformation.
D, if you are working in the computer blank screen choppy, this is the effect of voltage instability, and will return to normal when the voltage is stable.
2. display flashing
May monitor computer signals cable is loose, you can plug it again. There may be display adjustment buttons at the bottom of poor contact, can settle.