STOP !
Smoking in an EM is a Serious matter that needs to be dealt with properly. It will be a "locked on" coil - either a bumper or a relay. You need to locate the cause of the issue. As mentioned, if it is the bumper, check the switch. The chime and 10 or 100 pt relay may or may not go off, as it is common for the second set of switches on the bumper switch stack to be broken ...
Please locate the smoking coil.
It could even be the second switch stack is open - causing the "B" relay to stay "on" - But this will cause the chime coil and scoring coil to stay on.. this is switch issue and it needs to be fixed...
First check - compare the switch stack in each bumper.