Measuring TT Speed

Get the app "RPM" on your phone. Not only will it give you the speed but also Wow and Flutter.

If the belt is too tight, it may be causing the motor bearing to wobble by applying a bias to one side. Try backing off on the motor mounting screws if possible.

Is the belt made by the original manufacturer? Treat the belt with baby powder and try it again. Use only original belts. RPM is much more accurate than the strobe routine. 

WoW is every rotation, fludder is intermittent? Or is that backwards..
Been a while.. If the belt is in a grove and the NEW one is just a hair to wide, as the belt comes off the pully and out of the grove, BOING! it snaps out..

Make sure there is not a wide spot. Mark the wide spot, trim if needed (with sandpaper), and re-powder the belt.. BUT wipe and clean the pullies.. DON’T forget.. A sticky spot on a pully, can drive you nuts...
Slipping belt, whole different thing, touch the platter it stops... Slow startup.. la te da.

Regards