Turntable Hum And Channel Drop

Yes, alligator clips would be fine just to test the hypothesis. 

Do you think a wire has shorted?  If so, what could be the cause?  I haven't moved or handled the tonearm or turntable at all since this has started, just normal record playing.

Got to be the wiring.

Thanks for the info.  At a pretty consistent point when the tonearm travels across the record, the left channel sound quickly gets quieter then is gone.  And it comes back when the tonearm moves an inch or so further into the record.  What would be a suitable way to ground the aluminum foil?  Would alligator clips soldered to a length of wire work?

Star Sapphire has motor under the platter, I think. If so, problem could be EMI from the motor. Some cartridges are more sensitive than others, but I don’t know why the problem evolved from nothing at first. Try shielding the motor with even a piece of aluminum foil placed between motor and platter. Ground the foil.

Check with Mark Baker at OL. I seem to remember there was an issue with the internal wiring.

What do you mean by the fade out a few inches into the record? Music volume decreases?