Also.....take a look at the end of stroke switches. For example, take a look at your flipper coils and you'll see that at the end of the stroke the armature separates a switch that is normally closed. You want the switch to open at the very end of the stroke because both switches are actually feeding current to the coil. The switch opens at the end of the stroke to keep from burning up the coil. Because of the amount they are use these switches get out of adjustment and therefore weaken the coil creating a loss of power in the flippers. Its a quick easy fix that has a big impact on play. Also make sure those end of stroke switches are clean.......I use a small metal file on them because of the metal used in those high impact switches. Should be the same on your pop bumpers as well.