Dvd picture disappears

probably a failing connection between the rear panel jack and where it interfaces with the PCB.....unless you are an electronics engineer I don't know what you can do besides send it to the manufacturer for repair. If it has any other outputs you could try those just to isolate the problem.....I am not sure what type of connection you are using currently....component? HDMI? but try a different one and see if the problem still occurrs...at least then you will know if it is isolated to that one output or if all outputs do the same thing.