NEWBIE-need help with sons train-whistle/bells/crew not working

This is are 3rd christmas, and the 3rd timeusing the train-the sound isnt working-it is a lionel northwest special freight 6-30047 the switch is in the “on” postion under the locomotive…is there a easy fix or test, or should I take it to a repair shop. Thanks Scott

[#welcome] to the neighborhood !

If there are no sounds at all, including bell & horn, try adjusting the volume control. Sometimes the volume control will develop some corrosion or just get dirty causing intermittent or no sounds, using a small screwdriver rotate the control knob back & forth a few times. Now turn it in the direction which is max volume to the stop and then back off a little bit.

Hope this helps.