I’m trying to revive a Beogram RX2 (model 5833) that I purchased in 1988. It’s been in storage for years. Unfortunately shortly after the tone arm lands and plays the first few turns, it skips backward, plays a fews turns, skips back, repeat. I investigated under the platter and there’s nothing obviously wrong. The tone arm moves freely when it is in the raised position, but when it drops to playing mode there is a small force that pushes it towards the rim of the record. (I verified this by removing the platter so that tone arm drops into free space: no matter where I cue from in the up position, the arm swings right to the rim soon after it drops down.) It doesn’t seem to be a lubrication problem because everything moves freely. The cartridge is the original MMC3 and the down force is set to 1.3 grams. I increased the down force to 2 grams and the same thing happens. The antiskate setting (on the underside) is set correctly for the cartridge. The cartridge and stylus appear to be in good condition when I inspect them with a 5X jewelers loupe. Any pointers on what to try next?