3DS doesn't charge (new charging port already installed)

Hello and thanks in advance! I have an otherwise fully functional 3DS XL, however it doesn't charge. We already desoldered the old charging port despite it looking completely undamaged and intalled a new one. I'm not really experienced with soldering but it holds and all contacts are properly connected with the motherboard. We tested the circuit with a digital multimeter and all seems to be fine. We tested continuity between the charging port and the battery connector and it shows the same values as a 3DS XL with functional charging port. What could be the reason for this behaviour? Is some part of the motherboard damaged?

Best regards,

Johannes