Why you think, you need a new board/mpem? Is the 5amp fuse pop'n? Theres a few possibilities that might contribute to "faulty" mpem. 1, is to disconnect the yellow and red wires from rectifier, see if fuse still pops, and 2, if model has "vts", disconnect it, that'll contribute to pop'n fuse, too.
If the board is bad, Seadoosnipe, has ability to remove the "potting" soil, and for what its worth, if board is bad, won't hurt then, for him to take a gander at it...