you will have a fried transistor at least for sure in the special solenoids section of the driver board. you could even have a fried driver transistor and I.C.
which pop bumper was it so i can work out which one it will be.
+1
Also check the diode across the transistor - The coil it toast, but it is always good to find out "why". There's also a capacitor across the pop bumper switch. Make sure that is not shorted, or you will blow the repaired board.
Did the pop bumper pull on when you switched the game on, or while a game was in play ?