Technosonic lcd lcd1908 monitor

my technsonic 19" lcd1908 keeps going of the pc channel and comeimg back onto the (128 auto fm-auto channel) the green light does flicker on the monitor when this happens and to get the pc channel back sometimes i have to turn monitor of and back on then press button on control for pc i have no scart connected to monitor just pc.

no replys suppose this never happened before to anyone???