Hey guys! First time posting on pinside. I'm having a problem with a stuck (on/engaged) left pop bumper ONLY when I actually start the game. I have recently purchased a space station and I just finished removing the Mylar, and replacing the MPU with a rotten dog one. Had battery damage. Everything worked great once rebuilt and put back together except the left pop bumper did not register very well. I adjusted the switch and over adjusted it the first time. When I turned the game on, I noticed the pop bumper was stuck down as soon as I started a game. I then shut if off within about 10 seconds. I readjusted the switch and it it worked great. A little later it got stuck again. I adjusted it again and it worked but was not very sensitive. Once I tried to adjust again. Power off, with the adjustment tool It is now ALWAYS stuck on ONLY when I hit the start button. However when I first turn on the game It goes through the pop bumper and coil test and it works fine. Even returns back to resting position. Only when I hit start does it stay in the stuck position.

I'm new to working on pinball machines, but based on what I did, maybe i shorted something out when incorrectly adjusting the switch? Based on my research if i damaged something the coil would stay engaged as soon as I power on the machine and that is not the case. Maybe a bad diode? Where? Maybe the capacitor on the leaf switch is shorted? Any help would be much appreciated.

Thanks, Jordan