What circumstances need to replace the Main Control Module

(1)   The Main Controller Module has a black screen. When the multimeter measures a DC voltage between PV + and PV-> 400v, the Main Control Module needs to be replaced.

(2)   The data of the combiner box cannot be viewed in the background, and the settings (baud rate, parity, address) of the monitoring module are correct.

(3)   Remove the RS485 communication cable of the AB terminal of the controller module and measure the DC voltage between the AB terminals is less than 2v, you need to replace the Main Control Module