Hud, everyone should thank you for your post. It cant be said enough how important it is to check the voltage on any troubleshooting situation. Its ALMOST ALWAYS about the juice. Im not good at mechanical stuff but in dealing with feeders and all the guys I hunt with we all agree that the huge amount of feeder problems are about not getting voltage. Definitely can be other stuff like bad timers or motors or something stuck or needing lube but the voltage is so often the problem and so easy to check it should always be the first thing to look at. It may be a bad solar or bad wiring or bad battery but those all come back to low voltage. Volt meter is your friend(if you hunt with feeders.)
I know I had already said my piece earlier on this but Ive found that so many overlook it that its worth repeating, and Huds real life example from just yesterday was too hard to pass up. Plus I couldnt resist reposting him saying he was stupid.

One of the first things you learn in electronics school. Always check the power supply first! And yes to the volt/ohm meter. You can track problems down in a hurry with one of those at your disposal.

Only two other instances I have had a timer not spin the plate......

1) once when I had pushed the spinner plate too tight up against the funnel of the barrel. The thought was less or. Would fee flow like around it in the wind and or the coons could knock as much out. Well, it was so tight it wouldn’t budge. I always check it can spin freely before refilling and after refilling.

2) the obvious wire disconnect or battery terminal corrosion.

It’s a good habit to check each source of potential issue PRIOR to refilling and AFTER. AND NEVER trust the battery read out display. Volt meter as mentioned above is included in all lease trips.