Quoted from Jeff_PHX_AZ:
My magnets all stopped working. All the sudden the coffin magnet grabbed the ball, held it and the hammer never went down, and the magnet just kept holding it, then after it released it, ALL magnets in the game no longer work. Game does have the upgraded magnet board as I checked the Stern website and matched up my serial numbers. Any idea where to look? Has this happened to anyone elses Metallica? Thanks
I know of a few instances with the transistor shorting out on the magnet board. After changing the fuse, start the game with the coin door open (interlock disabled), get a ball and hold it near the coffin magnet, then pull out the interlock to enable high power. If the magnet energizes, your board is bad. Disable the high power immediately so the magnet coil does not overheat. Leave the magnet board unplugged and you can play the game with the other magnets (disable the hammer in adjustments and set the coffin lock to captive ball virtual locks) until you get it fixed.
EDIT looks like you already got it resolved. Hope they figure out why these are locking on!