Sounds like a driver transistor is shorted and locking the coil on. A coil is just a length of wire, it isn't going to make much (or any) difference in this manner. The wrong coil certainly won't just burn up.

Please go back to basics and learn some things you will HAVE to understand or you are in for a world of pain.

Each coil will have a diode across it - this MUST be connected to the correct wire and sometimes the diode will be installed a different direction on the coil so you MUST look and KNOW which wire to connect.

SI has additional GI lamps being a wide body machine so the extra pin is likely for those extra lamps - I wouldn't worry too much about that stuff right now, it is unlikely to be causing your issues.

Do yourself a HUGE favor and spend some time reading ALL THE WAY THROUGH the PinWiki on Bally SS machines. A lot of stuff will come to you if you read this information that has been painstakingly put together by lots of people 'in the know'.

If you can't be bothered to study up on this then just pay someone to come and look at the machine because, while many things might be straightforward, many are not! IN fact, changing coils and not knowing EXACTLY what you are doing may well have damaged the driver board in this instance.