[morzh]

Das war meine vermutung.
But it was working until I touched it.
I could explain the LDOs'mounted on the heatsink pins breaking solder: they were seriously displaced.
But the connectors should've not been affected by it, they are vertical and connected to wires, having experienced no displacement. Vibration? Again, the connectors are light. Shipping vibration is not enough.
Vibration due to CD transport vibration? Dunno.
My hope is, I fix it so it is enough for another 30 years at which point I won't be around and so won't really care

But this thing is inconvenient to assemble.
The power board needs to be detached from the rear panel or else it won't go in. The rear panel cannot however fully detach as the power cord going through a cable clamp in it and then tacked to the board by another clamp held by plastic ribbed nails which is one time deal, to remove them I have to cut them. So the rear panel is hanging there interfering with maneuvering the board into the position and stressing the cord to board soldering spots.

A bear, a real bear.