Logitech z506 will not play through right rear speaker. When i switch the left rear and right rear speakers to their opposite ports (right rear in left rear and visa versa) the right rear will work and now the left rear will not. So i know that it is not a speaker issue and i have tried the test tones in 5.1 surround sound.
I have exactly the same problem, I still can not solve. I sent an email to the technical assistance and I'm waiting for an answer. I did all the possible tests but I did not find anything that justified the problem: /
I had the same problem. I am running windows 10 with a gigabyte 990fxa Motherboard. Windows, Gigabyte drivers did not seem to work for 5.1 surround. So I went to the company that makes the driver Realtek, http/www.realtek.com/downloads/.
I manually downloaded and installed the drivers from there. That fixed the problem with certain speakers not working. Now when I do the test I can test individual speakers.
High Definition Audio Codecs (Software) This is the one I choose to download.