I've been an owner of a PN50B650 since last September. Overall it's been great, but there are a few issues that still bother me a bit and I thought I'd ask before my warranty expires next month.
1) When watching football games, the green grass sometimes "shifts" in tone, like it can't decide what color of green to settle on. it's only occasionally and usually only when the camera is still, like before a play begins. This effect can be seen on a variety of channels/broadcasts. It is also is noticeable when watching certain animated shows, usually a pale skin tone might shift in tone a bit before settling. I actually had a service man come look at this a few days ago but really wasn't able to replicate it when I tried to (though I only tried with one game), but they had already ordered a new main board and just swapped it out for the hell of it. When he left I immediately found it to still be happening, so I tried disconnecting the cable box (was hooked up via HDMI) and tried it with component cables which seemed to lessen the effect, but not 100% eliminate it. However, it is much better than it was. I have the color settings on custom, though changing it between auto or custom or native never seemed to fix it before. It is a problem that bothers me but others tend to not notice.
2) I noticed when the service man was here that the model number on the service menu was listed at PN55b650 instead of pn50b650. I didn't say anything at the time (should have), but is that normal? I admit when I first purchased the TV I accessed the service menu but I don't think I changed anything at all, it freaked me out so I just got out of the menu. To my knowledge, there is no such thing as a pn55b650, just 50 and 58. Could I have accidentally switched this (or maybe this error was built in)?
3) This is probably related to the first issue, but when cinema smooth is on, in addition to the increased brightness (the CS "glitch") that everyone seems to experience, certain dark scenes fluctuate rapidly in brightness levels. turning off CS stops the rapid fluctuations, but even in normal mode I sometimes encounter this (albeit on a much more subtle scale) when watching dark blu rays. I have all the extra "enhancement" features turned off and it is in Movie mode.
I have searched much of this thread but I admit I haven't been able to read all 150+ pages, so I apologize if this was already covered. I'm curious if maybe the problems with #1 are just due to the HDMI cable, it wasn't very expensive but I was under the impression that all HDMI cables pretty much transmit the same quality of signal. Or maybe even the service menu listing the model as pn55 instead of pn50. I don't want to go back into the service menu and try to "switch it" (if it's even possible) without checking to see first. I really appreciate the help!