That same thing happens to Technics DD tables when one of the antique electrolytic caps fail. The good news is new caps are inexpensive, you should probably replace all of them when you go into the unit.
I did that to my MK2 and I'm having it done to my MK3. I suspect your P3 is suffering from the same problem.
I did that to my MK2 and I'm having it done to my MK3. I suspect your P3 is suffering from the same problem.