I bought a new turntable for my bedroom. It had to be fully automatic in case I fell asleep! It was fine to begin with then the tonearm stopped landing on the record and returned to its rest arm. Sometimes it then went repeatedly up and down on its rest arm. Manually, it plays fine. I don't wish to attach any blame at this stage so I won't name the shop and I don't want to blame the manufacturer either but I have to name them and the model to allow people to help me. It is the Audio Technica AT-LP3. There is a deeper mystery to this. The shop claims the turntable works as it should when they test it but it doesn't work at my house, about 40 miles from the shop. Any ideas what could be causing this. The turntable was placed in exactly the same position as its predecessor. It sits on the top shelf of an old Sony Hi Fi black ash cabinet. All other components are below the shelf it sits on. It is totally baffling. How can a turntable work in one location but not another?