Dolby Audio Drop Out with some Sources

[crewzer]

Need some diagnostic help and/or advice re Dolby audio drop out.

Problem #1: Front right channel audio regularly drops out when using HD FiOS /Cable box as source via digital optical cable or coax cable; problem is independent of selected HD cable channel. Sony STR-DE685 (old) receiver is set to Auto Decode mode, Dolby 3/2 (= 5.1) indicated, and blue multi-channel light stays on. Problem can usually be (temporarily) fixed by increasing/decreasing volume. Selecting 2 Channel sound field "cures" problem (right channel works fine), but system of course only operates in stereo mode.

Problem #2: Center speaker regularly drops out when using Wii as source and set for “Surround Sound”. Sony STR-DE685 (old) receiver is set to Normal Surround (Pro Logic) mode. Problem can usually be (temporarily) fixed by increasing/decreasing volume. Selecting 2 Channel sound field cures problem, but system of course only operates in stereo mode.

Blu-ray player works fine (no drop outs) as a source when using Dolby 5.1 [Auto Decode mode, Dolby 3/2 (= 5.1) indicated, and blue multi-channel light on] for BD’s or DVD’s, and also works (extra) fine with BD’s and multi-channel.

Everything else seems to operate nominally. Any ideas?

Thanks,
Jim / crewzer