I'm still having the issue with the garage door. It only happens after about an hour or so playing. Or if a ball hits it while it's opening. I'm not sure if the plastic thing would be the issue, since it opens 100% every time for the first hour or so.

I just placed an order to try out a new transistor. In the manual, it says that it's a Tip122 Transistor. Q20 on the board. They were cheap, so it doesn't hurt to try. Sounds to me like that might be the issue though since the garage door opens fine for the first hour or so. I'll let ya know if that solves it.

I installed the new transistor last night, but only played a few games since it was late, The door was working fine, but i don't think i was playing enough for the door to start sagging. I'm going to play a lot today, i need to wait a bit though, it's not even 8am yet. I'll post later on today to let you guys know if it solved the problem.

Edit: I just tested it. I played for about 1.5 hours straight. Had a few good games. Had couch and I&S multiball going many times, I also reached the Mystery Spot. The garage door was solid the entire time, it never sagged once, I haven't seen the garage door be that stable since buying the machine. So happy to have fixed the issue