You now need a digital to analog converter from Comcast with your splitter to receive channels above 29 when using their cable signal without going through their cable box. This is a recent change. Our Samsung set uses analog input for PIP and will work with the Comcast converter. No charge from Comcast for the converter. I had the same problem.
I have a samsung HDTV model LN37B650T1F hooked up to a comcast HD cable box & using a splitter to tv so I can enjoy my PIP function! Have had tv since Sept 2009 & have been using the PIP all along which has been great!!
However, last night the PIP was only allowing the very basic channels on the second screen! Prior to last night, I could watch any & all channels (basic, extended basic, premium, & HD) on main screen while being able to watch at least any basic & extended basic on second screen (I know I can't watch a 2nd HD channel)! Can't figure out what happened!
I checked all my connections & have it on right input as evidenced that I can at least access basic channels on second screen!
Anyone know what the problem could be & how to fix it??