Having problems with a sony 55 rear project LCD about 3-4 years old . Have a comcast dual tuner dvr hooked to it via hdmi. Having problems with the color intermitently going out but only on low def channels, the hi-def always stay ok and also when switching over to a DVD the color is ok. Just looking for a place to start, thinking of swapping the DVR out as a first step but my gut tells me that is wishful thinking. Any thoughts would be appreciated.

You might get better answers in the RP HDTV threads.

If the unit has a ATSC/QAM tuner you could try feeding a signal directly to it removing the DVR from the equation.