Do you have any idea between Comcast/Samsung how many different models there are? Hint: they all aren't the same(!)
Start by providing that info and we can begin to figure out what the techs are missing. Oh, and what other equipment is involved (again, all makes/models- receivers, etc.). Are you using HDMI cables, component cables, DVI? Have you tried different types of cables?? Understand, w/o providing all of these specifics, it's only us guessing to what you actual issue and parameters might be.
For the last 2 months my comcast HD cable box will be working fine and then it will show the letters DVI on the display and the TV will go black. I think the TV actually turns off when this happens. The DVR display goes from 1080 to 420 resolution. I have had 4 different cable boxes, 3 different comcast techs here and many conversations with Samsung. No one knows how to fix it

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