Greetings to all reading this thread. I have a reset problem which only occurs during the first 1-2 minutes after start-up. If I hit both flippers simultaneously the machine resets. Upon restarting, the left flipper button won't allow selection of a mission from the DMD. The right flipper won't select either, but launches the ball instead, while the launch trigger does nothing. After about a minute-and-a-half, the machine operates properly.

I've changed the varistor and thermistor. I have not replaced any bridges or caps. The power into the machine is rating well (the reset only happens at the beginning of play). All diodes are connected properly. The switch matrix shows all switches open, except optos. I pondered replacing the bride on the flipper board, however, if the bridge were bad, it would be resetting constantly. I can only feature the problem to be a bad solder joint or, possibly, an oxidized pin on one of the PCB connections. Whatever it is seems to be heat related, as in a continuity gap caused by contraction as the machine cools down. Once warmed up, the machine plays properly. Any suggestions before I begin chasing this ghost in my machine? Thank you very much to all who help.

Thanks for the info. I gave it a shot to no avail. What perplexes me is that when this occurs the left flipper button won't allow selection of play mode. And if I try using the right flipper the ball is launched, when it should allow selection of game mode as well. I performed a continuity test between the EOS on both sides, combined with the spinner (orange ground wire). Continuity is solid between all points.

The clue is in the fact that the right flipper will launch the ball while the left flipper will not select game mode. However, both flippers function during game play. My suspicion is there must be some kind of grounding occurring between the right flipper and the launch switch, which subsides once the suspect terminal, trace or component has warmed up enough to close the suspect gap and allow normal play.

...And what was your conclusion as to the cause?

Was your right flipper button launching the ball when this occurred?

Big70, your information about the opto board points in the direction where I'm currently looking. I also agree that cap 5 and bridge 2 should, ultimately, be replaced, since they're the original ones in a machine that's 21 years old and has been routed back in the day. I'll also take your advice about bridging the posts between cap and bridge.

Floyd1977, your point about the trigger versus plunger adjustment at A.2 16 is also a good place to look, regarding the ball launch issue.

So I may have two issues which simultaneously occur. I've repaired a few minor, weird things on this machine in the past, so this shouldn't be much more difficult. It's a matter of locating the origin and following it from there, which on this machine can be a tricky proposition. Now it's time to get to work and see how this pans out. I thank all of you for your time and support. This is a great pinball community. I'll revisit this post once I've isolated the problem(s) so others with similar issues may use this as reference.

Big70, I forgot to answer your last question. The answer is no, when pressing the right flipper button, the launch button does not show during testing and vice versa. All switches act properly during switch testing.

Problem solved! I pulled the power board only to find that C5 and BR2 have been replaced, albeit rather sloppily. Great gobs of solder, rather "cold" looking, combined with clear silicon gooped over the joints held everything in place. There was a bridge wire connecting the pos. posts, however, there wasn't one for the min. posts, so I added one. I replaced the board, fired the pin up and hammered the flippers. No reset and no more problems with the right flipper launch issue.

I've been in this hobby for 2 years now and I'm still learning a lot. The lesson I got from this was the realization that whenever something like this happens it's important to examine the condition throughout the whole machine before making any decision. Once I pulled the power board it became evident where the problem was. Had I done that in the first place, I would've saved hours on contemplation and tinkering. Any routed machine is likely to have "mystery" hacks done on it, and this machine was no exception. It plays great now!

Floyd 1977, I checked the setting on A.2 16. For whatever reason, when the pin would reset it defaulted into that particular mode (how odd). Don't know why but it doesn't do it anymore. Thanks for the tip. And thanks to everyone for your help.