Jiangsu baoshiyu measurement and control co., ltd is engaged in 475 manual devices. Let me answer your question. I hope I can help you.

Press the power-on key to see if it is turned on; If it doesn't light up,

1 depends on whether the battery pin is inserted into the communicator and tightened.

2 Check whether the system card of the lower 475 communicator is loose.

There is nothing wrong with the above, but there is something wrong with the machine.