Yamaha TT-400U

I recently acquired a Yamaha TT -400U in a bundle deal. I was hoping to maybe put a little work into and use as a backup turntable. Everything works on it except that the platter barely spins. I can see the capstan spinning, and if I go from 33 to 45 it does change speeds, but it's not relaying the movement to the belt. So I'm wondering, is it the motor, or possibly the belt? Or maybe some other component? I know this is a lower level turntable, so would it even be worth fixing? Any help or comment will be appreciated

The belt may well need to be replaced (it's past its use-by date if it's original!), or there may be gunk or "shine" on either pully (motor or platter) that's causing the belt to slip and/or the platter (spindle) bearing may be gummed up.

It is indeed a "lower level" turntable.

Thanks for the reply, I will definitely try what you've suggested. I'll post back with my results