Surface Pro 4 can not turn on by battery

A Surface Pro 4 computer, it can turn on by connecting the charger, however, it can not turn on by battery. in the Win10 system, it shows that the battery is charging and the capacity is increasing. however, If unplug the charger, the system immediately off. I am 100% sure that the battery is good because I tried install another main board and the battery is OK.

Could you give some advice on what kind of problem the first main board might have ?

Thanks !