I recently purchased and received a Denon DP-23F fully automatic turntable from a seller on eBay. After cleaning it up and installing an Audio Technica AT440MLA it sounded fantastic (looks almost new as well, especially considering it had a date code of 12/88 - so its 22 years old.) Anyway the tone arm is not automatically returning and the repeat function is not working. If I press the stop button, the tone arm returns flawlessly and the auto start is perfect. Any ideas on what could be causing this problem and how I could fix it?
These automations depend on mechanical linkages sometimes with also optical sensors which detect the arm position.
Generally they are frowned upon by purists because of the drag on the stylus applied by the mechanics and for that reason I would usually remove these before setting up an older turntable.
I'd recommend the same to you unless automation is something essential to you -- given that albums last around 25 minutes per side it's never been a great hardship to get up and trip the arm lever at such intervals.
The process for overhauling is much the same as for removal -- remove the platter and see what can be observed as you move the arm manually -- then if necessary remove the base of the turntable plinth and work from there. Look for mechanical links and electrical switches which are displaced -- and for optical sensors which have the same function and may have failed or been obscured by dust and fluff.