The magnets on LAH have a tendency to get locked on as you've seen in other posts, I would double check that isn't happening in yours before you put a heavier fuse in and the magnets get even hotter before burning the fuses out. Mine was doing that too before I put all new parts and did the modifications like you said on that little control board under the playfield but when mine got locked on it got the playfield really hot. Just don't want you to burn your playfield by putting heavier fuses in before checking the easy stuff.