An audio/video problem

For years we were using a 65" Toshiba projection TV for our video with a Dish receiver and a Panasonic Blue Ray player. HDMI from each box to the Toshiba to switch between the two. We were using the optical out of each going to the Denon AVR-1705/685. The Denon is old and doesn't support HDMI input. We used it to get some good surround sound. The poor Toshiba had a dying DLP chip and decided to upgrade to the 65" LED Samsung.
The problem we have is it seems the optical out of either the Dish, or the Blue Ray give no sound any more through the Denon. It seems as though at least one of the optical inputs works as I can take the optical out of the new TV audio into that input but the Denon will only lock on to Pro-Logic and not to Dolby 5.1 like it did normally depending on the program source being received.
Both optical cables give a nice light at the end when hooked to the opt/out of the two boxes. Any idea of why when the opt/out of the TV will not swing the Denon into Dolby 5.1 as it use to do from the boxes?
Thanks for any ideas and Bill, if I posted this in the wrong place, let me know.
Best, Jerry

jerryhawthorne wrote:For years we were using a 65" Toshiba projection TV for our video with a Dish receiver and a Panasonic Blue Ray player.  HDMI from each box to the Toshiba to switch between the two.  We were using the optical out of each going to the Denon AVR-1705/685.  The Denon is old and doesn't support HDMI input.  We used it to get some good surround sound.  The poor Toshiba had a dying DLP chip and decided to upgrade to the 65" LED Samsung.
The problem we have is it seems the optical out of either the Dish, or the Blue Ray give no sound any more through the Denon.  It seems as though at least one of the optical inputs works as I can take the optical out of the new TV audio into that input but the Denon will only lock on to Pro-Logic and not to Dolby 5.1 like it did normally depending on the program source being received.
Both optical cables give a nice light at the end when hooked to the opt/out of the two boxes.  Any idea of why when the opt/out of the TV will not swing the Denon into Dolby 5.1 as it use to do from the boxes?
Thanks for any ideas and Bill, if I posted this in the wrong place, let me know.
Best, Jerry

Jerry,

Wow, that's a tough one, I'm scratching my head on this one...

At first I thought maybe it was a incompatibility issue with the optical cables, but if you can get it to lock on Pro-Logic, the beam must be working good enough for the decoder circuits. I'm wondering if it is a matter of firmware incompatibility between the units as the new TV most likely has "upgrades" to its communications programming EVEN if it is supposedly compatible.

In laymens terms, I'm wondering (baring any physical device failure that just *happened* to start after coincidentally replacing the tv) if the old system recognized "HOLA" as "Hello" as the first handshake signal and then welcomed the data stream, where as with the new system says "I don't speak Spanish"....I give up... (I'm using languages just as an example to represent the data throughput).

Other than that, nothing I can offer for troubleshooting.

Thanks Dr. Radio, I too am confused.  I will try the opt/out of the TV and make certain that both (by switching) that the opt/in on the Denon are working.  Was a little doubt about both working before.  It is convenient to go from the TV opt/out to the one we  know is working for the Denon as all sound goes to the Denon with no need to switch audio input on the Denon.  I swear the sound was better when things went to Dolby 5.1 before.  Just confused.  I'm not certain what the difference is between PL and Dolby 5.1 but with my surround sound it just seems 5.1 sounded a lot better.

Best, Jerry