On January 29, 2019 at 09:29, highfigh said...
Do you have a small TV that can be placed near the cable box and connected via a short HDMI cable? Try that and if it still does this, connect a component or composite cable. If it still does it, return the cable box, but make sure the connections from the demarc point to the cable box are good, the ends are terminated properly and you don't need a DC block on the feed.
^^This for sure. A test monitor at the cable box should at least tell you cable box or receiver (it is related to onkyo). Also, you didn't mention what brand the fiber HDMI was. I have not used any of them out there, but I have had great luck with the high end Ethereal active-super-ultra-Velox. (though I don't know your run length or if there's Carlon available)
As a Minnesota guy, could it just be the Timberwolves? LOL, sorry...
Also, on the cable line, is there a powered Commscope splitter involved?
