My Denon DRM-550 does everything, except play.

[dankik]

Make sure they are the (Y) variant... 1.2-3.0 mA. Some of the ones that I saw were (GR).

 

[Frank Wild]

Make sure they are the (Y) variant... 1.2-3.0 mA. Some of the ones that I saw were (GR).

The night before last, I replaced ZD301 with a new one and to my astonishment, the
music started playing, with meters and all. I immediately turned it off and went to bed happy.
I planned to update our discussion the next morning with the great news.
Before doing that, I tested the machine once more, and it's the same as previous. For a while,
I even wondered if I'd had a late-night hallucination, but it wasn't.
I do have a better ground-to-anode reading on that diode since replacing the original one: about half a volt now.

Yesterday, I once again replaced ZD301, since I have 50 of them now. No change.
The JFETs TR101 and TR201 should be arriving soon --they ARE the Y variant--, and I'm not very optimistic about that solution, but it's worth trying.
I have an IC302 on hand, but changing that is a little more involved, so I'll probably try the TR101 and TR201 first, especially as you told me that
the IC appears to be doing its job correctly with the voltages it's being given.