ONSCREEN

Some of our Xfinity customers have seen "No Signal" on the TV when they configure the Pass-through option.  In this case, the HDMI cable from Xfinity is plugged into the ONSCREEN HDMI In port and the ONSCREEN HDMI Out port is connected to the TV. After rebooting, the TV shows the Xfinity programs fine, but when a call comes over ONSCREEN the TV shows "No Signal" when going back to Xfinity.

This is a problem with the TV syncing back to the Xfinity signal.  It should clear up if you follow the instructions from Xfinity to set the display resolution of the Xfinity cable box to 1080p instead of Highest Available.

<a href="https://www.xfinity.com/support/articles/x1-video-display" target="_blank" rel="nofollow noopener noreferrer">Here is the link to Xfinity instructions</a>.

Adjust your video display using the X1 On-Screen Guide

Learn how to manually configure your video display using the Xfinity X1 On-Screen Guide.

Note: Your X1 TV Box will automatically configure to the highest video resolution possible for your TV at setup. If you want to manually change your video display settings after setting up X1, follow the steps below.

Press the xfinity button on your remote.

Scroll over to Settings (the gear icon) and select it.

The Main Menu is displayed, with the Settings at the lower right.

Highlight Device Settings and select it.

Settings screen. Device Settings is second from top.

Then, navigate to Video Display and select it.

Device Settings screen. Video Display is second from top.

Select Video Output Resolution. On this screen, choose your desired resolution and press OK.

Video Output Resolution screen with available resolutions.

Once done, you can also toggle Zoom between Full and None.

Zoom option, currently set to Full, is at the bottom of screen.

1. Press the xfinity button on your remote.
2. Scroll over to Settings (the gear icon) and select it. 
 The Main Menu is displayed, with the Settings at the lower right.
 
3. Highlight Device Settings and select it. 
 Settings screen. Device Settings is second from top.
 
4. Then, navigate to Video Display and select it. 
 Device Settings screen. Video Display is second from top.
 
5. Select Video Output Resolution. On this screen, choose your desired resolution and press OK. 
 Video Output Resolution screen with available resolutions.
 
6. Once done, you can also toggle Zoom between Full and None. 
 Zoom option, currently set to Full, is at the bottom of screen.
 
7. Press Exit to return.

xFinity plugged into HDMI In works until you have a call. Then it shows No Signal on TV.

Adjust your video display using the X1 On-Screen Guide

Video display