I tried running the test. It seems left or right channel still does not have a signal. Being that the Raspberry Pi has at least two sound drivers on it, I made sure that the UDRC soundcard was the default system.
I also use the DRAWs Manager page and set all levels to zero, and also in the Audio driver page (Right Click on speaker icon on RPi task bar) I set all IN2 to 10k. I noticed there was both Positive and Negative, so both were set to 10k. I hope I did this correctly.
Please advise, and thank you for your help,