Well my sander started running the belt off of it three weeks ago and I have replaced all the parts I would think would be needed and still no luck. It is an old pneumatic bridgewood 15". They no longer make them but the new grizzlies still are very similar and still use the same parts. I have downloaded a manual and made all the adjustments but nothing seems to work. I have a video of what it's doing. I don't think the top head is oscillating fast enough to turn the paper in time and it's hitting the cutoff switches and running off of it.

Here is what it is doing
https://youtu.be/1D2XCWlDkII

Have you tried a new belt or two? I looked at the video That looks like a nice sander but more complicated than what I have used..  My only experience with a edge sander is using my Grizzly 1140 (with pattern sander) and little Rigid combo. 

Did you replace the top drum wheel and bearings?

Figured it out today guys thanks!

Good to hear Tom!! 

Ah come on, TJ..

What ya do to fix it?