There are multiple things to take a look at with this.

  1. First check if there is a 4 port A/V switch and see if the right port is pushed in to display the video of that port. Typically the community channel is port #1.  You can go through and push each button on the switcher though to see if possibly your community channel is on another port.  A lot of customers have this 4 port A/V switch so you can share one cable tv channel with multiple devices such as live camera feeds for chapel services and activities, then also DVD/VCR players for showing residents videos.
  2. Next if that doesn’t work then power cycle the channel modulator.  So if your in house channel normally shows on channel 2 then you should have a modulator in the same rack with the PC that says “2” on it.  Go to the back of it and locate the power cord and then unplug the modulator, wait 15 seconds and then plug it back in.
  3. Finally if your PC is using an adapter on the back for changing from an S-Video output to a composite output then re-seat the S-Video adapter and reboot the PC.