The green lamp is the indicator of the power, when the lamp is off, maybe:
1.The power is off. Please check the power, if the power supply is ok, please call a service.
2. The lamp is failure. In this case, most of the freezers run normally, only need to replace a lamp.
If you find the lamp is off, please check if the freezer is running normally, because for some freezers, if the green lamp is failure, the freezer is off.