Marantz CD63 & CD67 mods list

@Barry again: Did i get that right, you're using a Tentlabs Clock? If so, the XO will probably be sitting on a socket and it COULD be that one of its pins doesen't have proper contact.
You could try and remove the XO and put it back, maybe a slight bending of the 4 legs can tighten its fit. But careful, the XO is also ESD sensitive and can (already has?) easily be damaged.....
Just a thought.
Mickie