I'm trying to be a detailed as possible to get as much help as I can. Sorry this is for the Length of the post.

Earthshaker: My three pop bumpers and shaker motor weren't working after a brush motor replacement. Testing showed on the Aux power board 5J11 pin that should be 25V I was getting nothing. So first I checked fuses all were good. However the previous owner had all the values incorrect. I know I should have checked that first before turning it on but I didn't. I recently installed new brushes on the motor kit and that is when my 3 pop/jet bumpers quit working. I think the new brushes were rubbing the housing of the motor and caused a short as the motor didn't work at all. So I removed brush kit adjust tested continuity and could tell that both lugs were indeed grounded to motor housing. I was a bit surprised a fuse didn't blow when those brushes shorted to motor but again I didn't realize the wrong fuse values were in the board.

After checking and replacing all fuses motor and pops still didn't work so I searched pinside I was tipped off to check W4 because of a post on Pinside where someone was having the same issues of pops/jets not working along with shaker motor not working. Theses components all all share the Red-White wire for power from 5J11 pin 11.

So armed with pinside knowledge I did some testing and found the the 0 ohm resistor at W4 was not showing any continuity or even registering with my ohm meter. Once I replaced W4 with a wire jumper removing the old 0 ohm resistor the Pop bumpers and shaker are working however I noticed the shaker seemed really really fast... It's also got a bad resistor on (R108) on quake motor's drive control the MPU so it's stuck on. Since I noticed how much faster it was spinning I unplugged the harness to the motor high current board I decided remeasured the voltage on the Aux Power 5J11 pin 11 and it this time it was showing 41 volts DC not 25V yikes!!! No wonder that motor was so fast.

I wanted to record a video of the motor spinning as sometimes it doesn't want to start up if it stops in a certain spot and while recording I saw the magic white smoke come for R1 on the high current driver board for the shaker motor. I turned off the machine and disconnected the High current board then I turned it on once more to see if the 2 jet/pop bumpers were still working and they are.

Since confirming that pop bumpers are still working I've left it off because I'm concerned about the 40 volts I'm seeing going to them.

I've only had this ES a few weeks and when I last tested it (before brush install) had correct voltage on 5J11 pin 11 of the Aux Power board. I know there are jumpers on the board that can change this voltage so perhaps I'm using the wrong jumpers?

I checked the transformer's 25 volt taps and they are indeed putting out around 30 volts AC. So I think I might have and issue with the Bridge Rectifier however just wanting to confirm with y'all as I'm all new to this hobby of working on pinball. It's been a decade and a half since my electronic repair class in high school.

Also done at the same time of Jumper W4 was re-flowing the pins on the Aux power board for 5J11. Also previously tested the Q79 quake motor driver on MPU it was good as well as the other transistor in the drive circuit but again R108 was reading about half the ohms it should so I think that is causing the motor to stay on.

Is the bridge rectifier needing to be replaced or do I have my jumpers wrong but I think W4 is where it needs to be.

I'll post some tomorrow when I'm back at work on the machine.

I was more concerned about the High Current Driver board and the Earthshaker's Quake motor. I had the nice puffy white smoke come from R1 of that resistor.

So I guess I need to find out why if this is normal did it fry R1 resistor on the Shaker Motor's High Voltage Current board.