You need to get the schematic for the game,  and locate what actually drives the coil.  Could be a short in either the CPU or PPB, check the transistors, pre driver transistors, diode and resistors in the circuit.

OK had a quick glance at the schematics, check Q1 on PPB and check Q13 and Q7 on the CPU.  These are the transistors that drive the coil.  Hope it helps.  LAH is a fun game to play.