After several minutes of being on the initial setup screen pops up on.

I have a Phillips 42pf7 flat screen not one mentioned above but was closest option. After several minutes of being on. The initial setup screen pops back up again. I clear it off and randomly it pops back up again. I have taken the batteries out of the remote Incase it was from a stuck button but too no avail. Have bought new digital to analog converter box still no help. (I do digital to analog because I use the tv only as a monitor for my home security cameras and they require an analog signal). Any suggestions?