I bought my sharp 37inch lcd tv about 4 months ago every now and then when i switch it on the picture does not show full screen only a square in the top left corner and a pink colour along the bottom.switching the tv to stanby on the remote then switching back on does not solve the problem it comes on exactly the same, the only way to get the screen back to normal picture is to switch the tv off from the mains then turn it back on again, has anyone experienced this broblem and what is the cause of why this happens.