STTNG keeps loading and shooting balls on start up

[dschulpius]

I all. I'm sure I read about this problem some time ago but can't remember what the cause and fix is. Before I spend hours troubling shooting and replacing opto switches and stuff I thought I'd ask to see if anyone can give me an idea of what might be causing this:

When I first turn on my STTNG and it finishes booting up it will load a ball into the shooter lane, launch it and the ball will disappear  under the playfield under the borg ship. Next a ball will pop up into the right cannon, the cannon will rotate and launch the ball onto the playfield. It will then roll into the ball trough. This behavior will repeat forever until I turn off the game.

Also, before this started happening when the game was playable I'd get a random ball added to a game every once in a while. Actually at least once a game. Could this be a clue as to what's happening now?

Thanks for any ideas or tips!

[BigMatt]

Makes me wonder if you have a diverter locked on or maybe one with a broken wire? It sounds like its trying to load the other cannon and cant becasue of a diverter and ends up clearing an extra ball on one side,,, Otherwise youd have some switch errors logged. Take a quick look under there and test them

[CUJO]

Check for divots in the ball trough. I used the plastic liners you can buy to let the balls roll properly in the trough.
Or if the original ball trough opto boards, may be time to retrofit with a new set with status LED's.
That's what was wrong with my ST:TNG. An intermittent wire connection going to one of the trough opto's and the divots in the trough.

[HammysHangout ( Hammy )]

check optos in switch matrix, its trying to reload the cannons.

[k7]

ya, i'm thinking to watch switch test, by loading the ball trough 1 ball at a time, and if those check out, use a ball (by hand), to load the cannons
to see if those switches are operating.

doesn't star trek, the next gen suffer from that 16 opto pcb as well? there's a modern replacement if that ends up being your problem, but test
everything the right way, don't just throw a board at it.

[dschulpius]

Thanks for all the tips guys. I appreacheate every one of them. I've had this pin for decades and have worked on it many time over the years to keep it running properly. I've filed the trough grove to keep the balls rolling, worked on the opto board under the PF a few times, replaced and fixed opto switches and replaced the cannons wiring, sound board repair and replacement among other stuff.

After a repair it seems to run nice for a few years then something else pops up. Ugh, LOL. I know it's a pinball machine and things break. However this one seems more prone then the other ones I own. I was told years ago that owning a STTNG is not for the faint of heart or a novice that can't fix a pin. I guess that's the truth. LOL.

Sorry, just blowing off some steam. I really like this pin and don't mind pin repair. I guess it's time to look at some of these new solutions mentioned like the ball trough liner and new opto board. I'll follow up with the fix when I do it. No hurry though. Lots of other stuff going on. 

[HammysHangout ( Hammy )]

90% its related to that shitty 16 ch opto board and/or dirty optos , you honestly need to clean the habbitrails on that game every couple 1000 games.

[dschulpius]

OK, reporting back in about this issue. I found out what was going on and fixed it. Turns out the top diverter under the playfield had it's coil swollen up and jamming the diverter closed. Along with the bad coil I found it's transistor located on the little 8-Driver PCB blown. So I replaced the bad coil, pulled the little driver board and replaced the TIP102. I also replaced it's pre driver transistor for good measure in case it was stressed also. Oh, the fuse feeding this solenoid circuit was blown too.

So all is well and the game is playing good now. I did still get a random extra ball on the PF at one point during one game. I guess I'll fight that issue another day. Maybe a flakey or dirty opto. The game is really clean though but ya never know. LOL.

Thanks for the help guys. 

[BigMatt]