"TV works as expected when the receiver is off" - through the tv speakers or through the receiver?
"hdmi cable running from the tv HDMI out jack" -- HDMI jack of what -- the receiver? --
Enough questions. If you're going to run all sound through the receiver the HDMI out of the cable box should go to one of the HDMI in ports on the receiver. I didn't read the Yamaha user guide but if you have HDMI pass through on the receiver -- you may want to disable it on the receiver and see what happens. Make sure you have the correct signal source selected on the Yamaha (HDMI 1, we'll say, for the cable signal, FM for the radio, etc.). Receivers are not known for pulling in FM stations without an external antenna, especially if placed in a home theater cabinet or whatever.
The successful pinging just means that the Yamaha sent a signal directly to the speakers through the speaker posts.
I just bought a new Yamaha V371 receiver paired with an also new Panasonic TC-P50S30 50" plasma. My intent was to replace my Harmon Kardon AV120 that has never been easy to use. I kept my Bose speakers and subwoofer so that was a plug and play.
Here is the problem. After I have everything hooked up, I get no sound from the radio (FM) or the TV. The TV works as expected when the receiver is off. I ran through the speaker set up and have successfully "pinged" my speakers (p24 user guide) by playing back a test tone. I have an HDMI cable running from the TV to the HDMI OUT jack. The other HDMI port on the TV is connected to my cable box (Comcast/Motorola box).
Any suggestions would be great...