I searched for this as I figure someone must have asked before, but couldn't find a concise answer. I have an old Panasonic Commercial Plasma (TH-PWD7UY) that is wall mounted in my bedroom. When I bought the mount, it was labeled as a Universal Mount I think for TV's 37"-45"... This was about 6-7 years ago when there were hardly any LCD's on the market yet, so I think the limitation was based on weight, not screen size.
I'm looking to get a Panasonic WT-50 LED 55" TV to replace this one. The weight of the 42" Plasma is 64 pounds, and the weight of the 55" LED is 33 pounds. Any idea of the existing mount will accommodate it? Obviously if they are rated by weight only than it will work, but I'm not sure if there's a size factor when the mount manufacturer gave the sizes it will fit.
The mount I'm using isn't a square VESA mount it's the kind with 2 vertical metal rails attached the TV, then attaches to the horizontal railing mounted to the wall, like this:
I remember it took a lot of elbow grease to get it in just right and it's very sturdy in the wall so don't want to remove it and replace it with another mount if I can at all help it.