you may have a crook pre driver transistor Q6
as far as the replacement transistor goes you should use a IRL540 for the P20N10

Hmm... if the q6 transistor is on the I/O power driver board then Q6 does not have a transistor... just 3 empty holes.... moon used to work fine tho.

Would using a p19nb20 insted of a IRL540 or P20N10 make the magnet not work now?