This has happened to a couple of my games. soon as the coil burns good and node burns enough it will stop. On my ghostbusters one transistor on node 9 got hot enough it melted the solder holding it in the node board. i found the transistor sitting in bottom of game. at least it unsoldered all three legs cleanly, new transistor slid right in. Never could figure out why there are no fuses. so far my GB has burned node 8 along with the right flipper coil, node 9 along with a scoleri coil, and when 9 went, so did node 9b, 9c. not sure why node 9 roasting burnt b and c also