This is a old problem that has plagued this machine since I took possession.. I started a topic on this awhile ago but I have lots of new info to share and a video so you experts can see the problem actually occurring..
While playing a 5 ball game.. the G relay is supposed to lock on after all the pins are knocked down the first time.. This happens as advertised, however.... While the G relay is locked on anytime I start hitting a flipper either side or both at the same time, the G relay will randomly unlatch for some reason.. The troubleshooting I have done are, adjusted all the switches on the G relay so that I get that nice crisp click when it latches.. all the switches are clean and I replaced the actual locking switch on that relay as well.. I also replaced the relay plate and out of desperation I replaced the relay with a new 9740 I had lying around. As you can see from the video, it only takes a few hits of the either flipper to unlatch the relay. If you look close you can see the relay bouncing randomly while I hit the flippers, then it just unlatches all together.
When I put the game on 3 ball the relay is latched from the get go but I can see it bouncing and trying to unlatch but it just gets re-energized so fast it never unlatches fully..
Also, as you can see, no scoring , the score motor isint running and nothing else is happening.. just a flip of the flippers and boom.
Ok please let me know what you think.. I am about to pull all my hair out of my head trying to figure this one out. Thanks so much.