The indoor elevator suddenly lights up blue and can't start.

There may be the following reasons why the indoor elevator suddenly turns on its own blue light and does not start:

1. Power failure: the elevator needs power supply. If there is a power failure, the elevator may not start normally. Blue light may be an indication of abnormal power supply.

2. Control system failure: The control system of the elevator is responsible for monitoring and controlling the operation of the elevator. If the control system fails, the elevator may not start. Blue light may be an abnormal indication of the control system.

3. Elevator fault protection: When the elevator encounters a fault or abnormal situation, it will automatically start the protection mechanism to ensure the safety of passengers and equipment. Blue light can be an indicator that the fault protection mechanism is activated.

Extended content: Elevator is a complex mechanical equipment, which usually consists of motor, control system and transmission system. In daily use, elevators may encounter various faults or abnormal situations, such as power failure, door failure, sensor failure and so on. In order to ensure the safe and normal operation of elevators, regular maintenance and overhaul are very important. In addition, the safe operation and normal use of elevators are also very important. Passengers should abide by the rules of elevator use and do not overload or press buttons at will to ensure their own safety and the normal operation of the elevator.