Ordinary electronic calendars don't show what's burnt out.

The electronic perpetual calendar is not displayed for the following reasons:

The first type: the power supply part of the perpetual calendar is broken, such as the burning of the transformer or the aging and disconnection of the power cord, which will lead to the failure of power supply.

The second type: the time control chip is burnt out. If the time control chip is burnt out, it will be very troublesome and can only be returned to the original manufacturer.

The third type: the electronic calendar crashes, just restart the power supply or restore the electronic calendar to the factory settings.