Sounds like a bad trough opto. Unfortunately, the two issues are probably unrelated.

Not ruined ,just needs work.The right cannon does sound like an opto,not sure on the other one.Maybe LTG will chime in!

I'm no expert, but have gone some rounds with STTNG recently and it is sounding like a switch matrix issue to me, considering your original problem and your current symptoms. Sounds like there's a short somewhere.

Just to confirm that I'm understanding you -- once the trough feeds a ball into the catapult, it feeds another before the catapult has had a chance to fire, causing a jam? Also, when in switch test, is your switch 37 going off like a machine gun (consistent and fast) or is it more sporadic?

Most importantly, do you have a copy of the operations manual? If not, it's available at ipdb.org. Look for the switch matrix layout.

Agreed. Definitely start there with the switch matrix and find the flaky switch or switch diode.

Yep - was just typing up an a post on the switch matrix. The Left Bank and Borg Lock are in the same row and Sw 37 and the Borg lock are in the same column. Look for a shorted switch.

I chased my tail for days on a TZ problem with opto and switch errors that suddenly appeared. Turned out that while replacing the bulb in the extra ball button/switch I shorted out the diode. Bending it out solved hours of frustration.

The borg lock is the above-the-playfield switch where it locks for multiball. The mission start is triggered by #47 under borg hole and it sounds like that's the one in question. I was looking for the same cross point ... the thing that jumped out to me is that the drop target switch intersects the L bank column and the row w/ both the under borg hole and the under r gun optos. The drop target is notorious for loose wires and tangles, it's definitely worth an inspection.

My buddies STTNG had a switch matrix issue and it ended up being the diode on the drop target had come loose. He actually ended up bringing the machine to my house for me to fix because he couldn't figure it out.

That does happen all to easily.

<Help!! I don't know what I've done to ruin the machine!>

Nothing more than give yourself an opportunity to learn and seek assistance. Overall, you are doing okay. This is how you will develop your pinball repair skills and be helping others one day. Just don't poke around under there with something metal unless the game is turn off (unless of course it is to diagnose something.)

Be hopeful. You'll soon be posting, "Got By with a Little Help from my Friends."

I had a quick learning curve as it seemed like whenever I went to fix something, I would create another FOG for myself.

FOG=Freakin' Opportunity to Grow

Yeah, that's definitely a switch matrix issue and it sounds like you are shorting something else across one of the rows.

The switch matrix and switch locations are page 94 and 95 of the manual. The way it works is that everything in a column is connected by a common wire, and everything in a switch is connected by a common wire. The switches you said you are are having trouble with are both in row 7. The "trough up" opto, which tells the game a ball is jammed in the trough and needs to be spit out, is also row 7, so I think we've localized the issue. Pay special attention to all of the switches in row 7 when inspecting for a short.

Remove the balls using the last test menu option, then raise the playfield. Inspect the switches to see if something is touching where it shouldn't be. You are looking for a loose wire that is touching another switch, or two terminals bent together, or a diode bent so that the metal is touching another component, etc. It could also be a diode that fell off a terminal or some other things. It doesn't necessarily have to be a problem with one of the row 7 switches, but that's the place to start.

I'd also go way all the way to the bottom playfield and find the drop target assembly that is behind the borg hole. Make sure that the wires on the switch there are intact and that the switch terminals/diode aren't wrenched. It's easy for that one to get smushed and it's also in row 7.

I'd say the fact that it changes behavior depending on the position of the playfield is even more evidence that there's likely a short across column 5 and row 7 and that whatever is doing the shorting is moving when you move the playfield. Now you've got to find it. With the game off, pull out and raise the playfield all of the way and inspect each of the switches in column 5 and row 7. Trace the wires that connect them and look for a pinch or exposed metal. (Some would say it's fine to do this with the game on, but because you've already got a short I wouldn't be too confident another, more serious one, isn't lurking around the corner.)

Did you find the drop target assembly and switch and inspect it?

Were you also able to identify the color of wires associated with column 5 and row 7 and trace them all the way through their path underneath the playfield? You really do need to inspect each and every switch in the chain as well as the specific wires themselves and it's not clear if you have done that.

The next step would be to ensure the short is on the playfield and not the boards, but the way the behavior changes with the orientation of the playfield sure makes it sound like you already have. There's a switch matrix test procedure you can follow and I'll PM you the doc if you want to go that route.

One other thought -- you could reseat the connectors on the 16 opto board mounted under the playfield. Could be something is getting pinched or intermittent there.

Beyond that, sorry to say you are hitting the limits of what I know. I'm still betting you are looking for a physical short under the playfield and haven't found it yet, but maybe one of the heavy hitters has another thought for you.

What do I win!!

..yes

I'm happy for you. this thread was an interesting read. It is very educating to read about other peoples pin-problems.
Thanks everyone for helping

Good work, thanks for taking the time to report back.