Why does my ds have loading issues

Thanks in advance but I have a new 2ds xl and I replaced the motherboard everything works it turns on fine volume ect all good but reads no game I get an error (but dose recognize the games) tired formatting it just freezes tired updating it same thing just freezes I get to the part where I'm able to search for a Wi-Fi connection and able to put in the password then hit enter then just freezes any ideas?