A:  
1. If the time setting on the display screen fails, please check if a button battery is installed on the back of the display screen; or check if the battery has power and try replacing it.
2. If the historical data or time-related functions in the MTR are abnormal, for RMX UPS units, check the button battery on the monitoring board; for HTX33 units, check the button battery on the monitoring interface board. Check if the button battery is installed or replace it.
3. If replacing the button battery does not solve the above problems, the corresponding monitoring board or monitoring interface board needs to be replaced.