I am having a few problems with the picture on my Tosh 42WH46. The problems are: On the very right hand side of screen, when the picture is showing an all white image (or any white image) there is a yellow tobacco coloured stain about 6-7 inches high and 2-3 inches inwards. This varies as u raise ur head up and down (it goes up and down too!). It also aint consistent being worse some days than other. I have heard someone else on these forums have the exact same problem. I was wondering if it can be sorted by tinkering around. Also I have a very soft blue circular discolouration on the bottom right of the screen up and in about 3 inches. Not very noticable in truth but in addition to the small diagonal dark yellow stain on the bottom left of the screen it all means some very slight annoyances in an otherwise superb picture across the remainder of the screen I have used the service menu convergence setup to tinker as well as normal convergence too but to no avail. I have heard experienced users mention the mechanical focus....I would like some advice on what this is, how to do it yourself and the potential dangers involved! Many thanks for any assistance provided.