My first thought was low 5v power with the mid game reset. Trying a different power supply board if you have one or have access to one. Definitely a CAP rebuild would not hurt.
One other thing I would HIGHLY recommend is to install fuse protection to your 2 B/R's. This is a known fire hazard if you get a short. System 11 Bullet proofing...
https://pinside.com/pinball/forum/topic/williams-system-11-bullet-proofing-thread#post-1211580