Sony sdm-hs75

when i switch on the monitor it shows  " information: eti: 00875 h" and then it disappears after sometime and then shows informtion abt the specs of the monitor ie. sr.no and model no. if i press the ok button or anyother button that too disappears but keeps reappearing and disappearing every 20 seconds or so.the display however works fine.the menu button of the monitor does not respond neither does the menu.please advise.