Repair for Lionel Holiday Christmas Train - O Gauge

Battery powered, RC? I would say that your local hobby shop might be able to do that.

   You'll get help, but more than likely its "do it yourself" help. A track powered unit would be somewhat different., but most of the cheaper ones aren't worth the cost of a repair shop, (sentimental attachment aside). Lionel had a part in producing some cheap ones, and really good ones both.

#1 Does that run on batteries or powered track? That is question #1 for sure.(no link, unfamiliar loco, & can't really tell)

Q.#2- Is this O gauge? Normally G belongs in the HO,N,G,Z section for best responses. Getting the size straight is why I ask. Post placing mistakes happen, and can be moved if it annoys anyone. 

    Parts aren't really made for the cheap ones either. But, they are normally very simple items IMO.

RC/battery op.- an RC shop isn't a bad idea.

 But..  Roll those batteries around a bit, and flip all switches back and forth on all items. Remove the batteries for about 10 minutes, and then reinstall them, try all switches again. Do that a few times too. (chips can have trouble "waking up" sometimes) Some have manual controls as well, try them. Turn the stack/ bell / domes, there are hidden switches there sometimes. Repeatedly unplug and re-plug the tether to the tender, or battery car if it has one. If you can, check that plug with a voltmeter or mini-light bulb to see if power even made it that far (any 6-14volt bulb should work to test there) Heck, push (lightly, don't strip gears, some won't roll) and generally bang them around a bit (if they are cheap, non-sentimental). Move or just push/tap on the metal contact rivets. Oil cleans rust (some eat plastics).

   I suspect mild corrosion on the contact points over anything. Moving switches, vibration, etc. often cleans things enough for them to work again. Like beating up an old flashlight .

If it is the set pictured, it is G gauge with a IR remote, constant voltage to the track.   The electronics fail and are not repairable.  I have converted some of these trains to run with a conventional DC HO transformer, but the IR remote can not be used nor will it have any sounds. Any local service station should be to do this conversion if you want to save it.