Ok, I have a 25" WG monitor in my MK1 cab. I do not know what model, but the chassis looks like it's the original that came with the monitor. It is clean and in good shape, but recently the picture has been acting up. The screen goes in and out of focus all by itself. It will stay focused for a while, go fuzzy for a second or so, then back to focused. This has been happening intermittantly for a while now. Anyone know what causes this or how to fix it? Many thanks.