Provided the turntable is in working condition and you have a new cartridge already it is nothing really special, just a few things to make sure the basics are ok.
- Does the platter bounce if you gently push the bearing shaft? Any strange sounds when the platter is rotating?
- Remove the outer platter and look at the motor spindle (where the belt is linked): does it wiggle when on? Any strange sounds from the motor?
- Now, with the motor off, make the subplatter rotate and notice if the rotation is smooth and centered (an inspection of the bearing shaft would be helpful: if it is damaged I can’t do anything about it); the shaft should not show signs of erosion and there should be no play while it’s inside the pit.
- Do the turntable controls work properly (on/off, 45/33 switch, tonearm lever)?