Which optical port in the back of the receiver goes to the optical port on the back of my HDTV

Hi sherring, have you cheked that your cable isnt damaged? the connecton at either end might be loose.

need to see the back of both units..

Is there a set top cable box, or are you feeding the cable directly to your HDTV (coax directly to the TV). If you are feeding cable directly to the HDTV then you don't need HDMI. There maybe exceptions, but most TV's don't have HDMI output. The only thing you need to run from your TV to the Yamaha is an audio cable. I assume your HDTV has an optical audio out (either TOS or coax.... Your Yamaha will accept either). Connect the optical audio cable to the AV4 input on the Yamaha. This way when you hit the TV scene button on the Yamaha remote, it will select the AV4 audio input (the default for the TV scene). The optical cable will feed the full audio signal, so that the Yamaha can pass through the surround sound or use the decoder as appropriate to feed your 7.1 or 5.1 speaker system.
If you have a set top box, you may be better off moving that near the Yamaha. In this case, cable goes to settop box, output of set top box via HDMI or component video (RGB) and optical audio to the Yamaha (if you use HDMI Input 2, and AV4 for the optical audio (if necessary), the TV Scene will select the appropriate inputs) and then an HDMI to your HDTV.
In case one, you may need to setup the TV to process the audio appropriately. I have experience with Panasonic Plasma but thats about it.

There is usually three ways to connect a TV to a Surround Sound system:

1. Optical Audio Cable (Fiber Optic)
2. Coaxial Audio Cable (Orange)
3. Composite Audio Cables (Left - White, Right - Red)

Once you select a cable to use that is compatible with both devices, you must then connect it to the output on the TV set, and one of the inputs on the Surround Sound Receiver (preferably the Video Input or whatever type you selected to use). Then you must change the input on the Receiver to the proper input that you connected the cable to (most Receivers will have a Source Button if not individual source buttons i.e. Tuner, Tape, CD, Video, Aux, etc.).
Note: Some Receivers if using a certain type of input will not have sound out of all 5 speakers unless the input is 5.1 compatible.

You will need the optical cable. My receiver only passes video through the hdmi. So I hooked up the HDMI cable to the tv, and the optical cable to the receiver. Once that is done you have to go to the audio settings for the PS3 and chose audio through the optical.

If you are using a Cable Box or Satellite receiver, use the digital input on video 2 or the digital coaxial input on video 3. If you are not using an external box, use the optical output on the back of the TV to the optical input on video 2. Depending on the manufacturer of your TV, you may have to turn off the internal speakers of the TV to activate the monitor output (optical) If you need further help, post a comment with the make and model of your HDTV and I can help you further. Hope this does the trick.

just press the DVD button on the remote contol and you will be ok.. :)

What port do you have the HDMI from you BD player into on the 510. If you have it on the DVD port then fiber optic will do you no good, the DVD HDMI only supports digital coax, the Video2 HDMI only accepts fiber optic, and there is an extra fiber optic for the Sat input. If your BD player does not have digital coax out, or if you dont want to buy another cable, just move the HDMI from DVD to Video2 on the 510. I am willing to bet you have the BD player plugged into the DVD HDMI port and the fiber optic cable from you BD player to the Video2 fiber input.