I have the same TT which I just acquired for almost nothing (part of a 4-pc purchase: Onkyo Amp/Receiver, Onkyo Dual cassette player, Sony multi 5-CD player, and Onkyo TT for a total of $25). The belt was completely gone - with much of it melted onto the platter. I was able to easily remove the old belt with a straightedge and wiped it clean with hydrogen peroxide, and replaced with a new, $8 replacement belt purchased on eBay.
After replacing the belt, the unit works properly.
An $8 repair is totally worthwhile. This deck has cueing (up down) and automatic return. It's not high end, but it does the trick.