Repaired screen, broke camera, need to replace but phone is from Japan

I repaired a screen for one of my foreign exchange student friends here in town. Afterwards the camera didn't work and after some research I decided that it was probably static that caused it not to function anymore. Yes I have tried replacing the camera multiple times (this is the front camera I assume but you can't use either).

The only way I really know how to get past this now is to get her a new phone or a new motherboard to put in the phone so that her camera will work (obviously cheapest method is preferred). How can I do this while making sure the phone will still work in Japan? Will an unlocked motherboard do the trick? Or do I have to buy from Japan?