Originally Posted by jpuck
I've had my new 3400H now for about a week and a half and the strangest thing is going on with my Xfinity XG1v4 box. I am constantly having to unplug it and plug back in due to losing signal. I have a Sony 900e and I'm always having to fight this thing. Xfinity came out yesterday and switched the box out but today it's doing the same thing. Whats weird is that I originally bought both a 940H as well as a Sony STR-DN1080 but somehow I ended up getting the 3400H as a 3rd option due to the rave reviews that the 3400H got online and it just seemed a premium AVR within the midrange price bracket. I am upgrading from a 920W and never had any of these problems with signal loss and I didn't have the issue with the brief time I had the STR-DN1080, just massive input switching lag on that receiver. I had the 940H for 2 days and both days I had to hardline power down the cable box. Anything I should be looking at under my settings or tips would be greatly appreciated.
I have the 3400 and Xfinity -- I'm not sure on the model of the box, it's the one that can do voice, amazon prime/netflix/youtube apps, 1080p60, DVR to other satellite boxes -- but I have not experienced your issue. I do have HDMI-CEC enabled and I see that the box does communicate properly with the receiver, especially in terms of powering it on when the TV and/or receiver turns on. Either way (with or without HDMI-CEC enabled to the box), I don't really have any kind of loss of signal in the way you describe. If anything, I might guess that your HDMI cord(s) may be to blame, as it resets with a power cycle (of sorts) and it seems to be intermittent enough. Even if the cable that Xfinity gives has all the right & top specs (which I have my doubts about in general), the cables between the receiver and TV may not; and/or these cables may have grown old and degraded -- I remember having these types of issues when first viewing 4k 60hz HDR video set up on my PS4 Pro.
Actually, come to think of it now, it might be a combination of your HDMI cords and/or the upscaling that the receiver does -- if you have it to upscale to 4k 60hz, it takes the xfinity box's signal of 1080p60 max and "processes" it -- then it would come up with this issues; either your HDMI cables does not have the specs for full 4k UHD resolution (which is 18 GBPS for the HDMI cable) and/or it may have gotten old and lost its "integrity" to pass that type of signal. You might be able to confirm this by disabling the upscaling (in Settings, Video, Output Settings) and see if the issue persists. If it does not, then this could be a stop-gap fix, but it is rather nice to get the Xfinity video signal upconverted and it would be a shame to miss out...
Good luck and hope this ends up helping...
My HT Setup 5.2.2---TV:Samsung Q6F(QN82Q6FNAFXZA); Receiver:Denon AVR-X3400H;Sub:HSU Research VTF-2 MK5;Speakers:ELAC F6.2(x2 -> Front R/L), ELAC C6.2(Center), ELAC B6.2(x2 -> Surround R/L), Onkyo SKB-750X(x2 -> Atmos "height" R/L);Sub #2:Onkyo SKW-750X;Connected Devices:Xfinity X1 HD DVR (TV shows), Sony PS4 Pro (UHD videos, gaming), Magnavox MBP6700(UHD HDR movies), Sony PS3 (UPnP media player), Nintendo Switch (gaming)