I have one of these and when I would play it about midway through a record it would skip, well I found out that the tone arm side to side bearing was dirty. I had to take the tone arm loose and pull it out to get to the bearing. I did not have to detach any of the wires going through it because I was able to get enough slack in them to pull the arm out to get to the bearing.
The way to check them is to first remove the needle, second adjust the weight so the arm floats, third set the antiskate to zero and pull the floating arm to the area about the end of the record and when you let it go it should stay there, forth now when you add antiskate to it the arm should slowly move back to the rest the more antiskate you add the faster it will go. Mine when I would do this would stop right in the middle. I cleaned the bearing and the race with qtips and rubbing alcohol. I did add a little oil to them but was told later that they were supposed to be dry but it does not seem to cause any problems. After learning about this I perform this check on all of my newly bought used turntables. Good luck