My First Thomas & Friends, Talking Rev & Light-up Thomas

Mine has stopped going. It will still light up and talk but won't go. I've replaced batteries. Any ideas on how to fix?

I bought this one to replace one that broke. This one doesn't talk it just chuffs and plays the Thomas song. Am I missing something here?

Is it possible to push the train manually without pressing the coal? Or when the batteries die?

Does Thomas move on the carpet when the coal is pushed or will it only work on hard surfaces?