Cannot get sound from blu ray via toshiba tv using hdmi cable

Optical leads have a red light that shows even when unplugged. If that is not on the socket is switched off.

The DVI adapter stops the audio. Use the audio out ports on the bluray player to connect an audio pair cable to the tv.

Have you attempted swapping out the HDMI cable for a different one? I recently had a similar problem and I determined that the HDMI cable was faulty. Now everything works fine.

onkyo receivers have a problem, see

http://www.hdtvsupply.com/hdmi-cable-booster.html

no just use the hdmi out on your tv

First, HDMI is not a perfect hook-up solution. Cable box connections via HDMI are notorious for being problematic. The best thing you can do is contact Samsung and get the latest firmware for your TV.
Samsung Customer Care: 1-800-Samsung (1-800-726-7864). If this does not resolve the issue, connect the cable box using Component cables instead of the HDMI. Component cables are HD also. I hope this was of some assistance.

as far as hooking up your blu ray player to the sc-pt660, the only real way to utilize the surround sound (with true surround sound) is through the optical audio out. You need to connect your blu ray player through hdmi to your tv and then connect your blu ray player to your surround sound using the optical audio out/in. I, personally have the sc-pt660 hooked up through component cables so I don't waste an HDMI input on my TV. Except for cd's, there is no reason for you to use the actual dvd player part of the surround sound considering you have a blu ray player. In conclusion, hooking your blu ray player and the sc-pt660 up to get better video simply isnt possible (your blu ray player alone gives the best possible resolution, 1080p). As far as audio goes, run an optical audio cable from your blu ray player to your sc-pt660 to get true surround sound.

You say this doesn't happen on regular cable or when playing a regular DVD. Hmm. Is this Blu-Ray player connected by simplink? HDMI is a bi-directional format cable, so  there are cases in setups where your tv can send commands to your blu-ray player and vice versa. It could be a problem with your blu-ray player that it is sending for some odd reason a mute command to your tv. Or is processing a command that your TV interprets to be a mute command when playing blu-rays. Because if it was the TV itself chances are you'd see this when watching a normal DVD or on cable as well. Since you say you're not, it leads me to believe the issue lies with the blu-ray player itself. 

Use an HDMI cable! It carries video and sound in high definition which is blu-ray dvd player. Costs about $25.00-40.00.

The best possible solution to your problem is :
Connect your blu ray player directly to the HDMI input of you Plasma and watch HD video....
and connect the 5.1/7.1 sound thru the optical or the coaxial link directly to your AVR 3805.
You will not loose anything on the Blu-Ray.
The sound is best processsed by the AVR3805, while the video, which is the real upgrade (BluRay) in terms of resolution of picture would be processed by your plasma.

Connect and Enjoy