Tv Has No Sound

You have no other cables connected to the VIP1200 except HDMI, power, and video in.

You have a HDMI to HDMI cable with no adapters. HDMI to DVI will lose audio.

Try a different HDMI cable.

If you recieve Cable on channel 3, then look on your remote for a SAP/MAIN button that selects the SAP audio or MAIN audio from the Channel 3 tuner....that's a very easy button to accidently push. You want to press it until you see main or stereo appear, you do not want SAP mode which mutes MOST audio.

Now, if you are using either the 3 wire RCA or the 5 wire component connections between the two then you want to RESEAT all connectors on both ends. They are notorious for slowly pulling out over time....

And if you are using HDMI then Unplug power from the Cable box for 5 minutes (do this no matter what connection you have ! )
Reconnect it, wait 2 minutes for the box to reboot and fire it up....you should have sound within one minute of turn on....

The LAST possibility...some cable boxes have their own volume control, and it may be turned down all the way.
Get your cable remote, set the top button to Cable (not TV) and then try the volume control again. You may see a totally different volume bar appear on your TV set if you do...max it out and leave it there.

Thanks