My faithful M1001 has been working without issue (except for having to replace the Power Supply Unit a while back). Suddenly there is no audio output signal and no output "spectrum" on the display. All settings appear to be normal, I've checked and rechecked the Network Setting and have restarted the Roku numerous time. All to no avail. Any suggestions on what to try or how to troubleshoot would be greatly accepted.

I doubt you have the volume turned down since there is no spectrum. I would try a factory reset.

FrankB:

Thank you so much for the reply. You're correct, I did not turn off the volume. Clicking the Volume control had no effect. Your suggestion gave me the courage to do a Factory Reset. After all, I have nothing to lose. Interesting result. After the Factory Reset and reconfiguration I can access my . But when I try to play a Favorite the screen displays (1 Try)(2 Tries)(3Tries)......  regardless of the Favorite I select. I think we've made progress since in the Off mode the screen displays the correct Date and Time and all the Favorites I selected in the past are recalled. So I seem to be connecting to the Server.

Any ideas of what to try now?

You are not alone, that's been reported here.