My Feet Hurt

I bought a really nice Thorens TD-145 turntable and one of the feet needed replacing. Since the original feet are really horrible, I ordered a replacement set that were more substantial, but still designed for Thorens tables. After installing the new feet, the platter will not turn. The screws for the new feet were a tad bit longer than the originals, but I don't think there are any critical parts near the corners where the feet are located. Any ideas on how to trouble-shoot this would be appreciated. I'm thinking of removing the feet completely and installing silicone rounded rubber bumper feet/pads on the bottom board. The table worked fine before I replaced the feet.
Thanks for the tip....that was the first thing I did. The seller of the feet (who also repairs Thorens) suggested I check a switch that controls that function. That's my next step, but I don't see how replacing the feet would have caused a problem with the switch.