Most times it is a weak battery. We suggest new quality batteries. If you see the light dimming, but it is still snowing, then change the batteries, this should correct the problem. (hint: you may need to twist the batteries to ensure they are seated correctly in the compartment) If your snow globe came with a plug try removing the batteries and plug it in. If you are still experiencing issues, please contact us.
Also, keep in mind many of our snow globes feature a timer. So, your snow globe may stop and restart on its own. This is usually a 4-6 hour timer. Some models are finnicky and require a rest in between stopping and restarting. If your snow globe will not come back on, move the switch to the off position and wait about 30 minutes. This should reset the timer, and it should come back on when you switch it to the on position.