Are the visuals working -- in particular the various spectrometer ones ?

The cs4231a chip is required to make those work from tuner/aux, but not from mp3 playback. Can you try tuner/aux?

Since the hard drive is working, we know it's not a simple stuck data line like the previous bad player I diagnosed. And you say ethernet is working, so that's good. How about USB?

If USB is good, and tuner/aux visuals don't work (the bar graphs and spectro ones), then the cs4231a *really* is bad, so no need to send me the board.

Cheers