As it’s getting old and I hope it not the laser. As this Sony laser now is like rocking horse s**t to find new.
WADIA 16 4 x PCM1702-K dacs
VRDS CMK-3.2 transport mech
Sony KSS-151A laser.
If it is something in the analog output stage, it looks easy to get at everything for measuring from the 4 x PCM1704 dacs (with red dot on them) back to the rca and xlr sockets.
https://postimg.io/image/4xqllxhul/ You can click on this image when it loads for super high rez