There is no way you or anyone else is going to know that, until you take it apart and work on it.
Looking the boards over, it might be something obvious. Like a blown cap, charred IC, etc. If you don't have any schematics to go by and/or experience with repairing electronics; then you can just try doing the board swap thing.
I would start with taking it apart, pulling the 2 suspected boards and looking them over very carefully. See if anything is obvious.
If not, then I would start with the power supply, since it is the cheapest to replace and not likely to be damaged by anything else.
Just make 100% sure you get the correct boards. Manufacture can use 2 or even 3 different board these days on the exact same models. Just depends on if it was an early production run or late. Especially on main boards.

I have fixed many devices over the years but I'm not a repair shop. I'm not setup to do that kind of work, especially these days.