You should be able to get the parts in the US from Yamaha's online parts service 'Yamaha24x7'
https://www.yamaha24x7.com/#/ but these days you seem to need an account even to check for a part!
If you decide not to replace the complete AM board, then note that there is a thermal resettable fuse immediately after the DC power socket: TH090 part no. VV45800R, PROTECTOR SWITCH RUE250, RUEF250 2.50A 30V.
Hopefully this is OK and has reset, but you might want to check for continuity across it with a meter just in case it was damaged during the 'incident', whatever that was. There is also a diode next to it: D0090, part no. VR313500, DIODE which you can check.
From your description it sounds as if there was a short circuit in the DC socket or plug, and if so hopefully it will only be necessary to change these.
Regards
Ian