You probably do have to remove a lot. Call stern and ask though.

This also happened to me after about 50 games. Really hoping I don't have to lift the entire playfield but the optos are still in the mail and i'm waiting for instructions. If you found an easier way to do it please let me know.

Sadly no easy way to do it, you will likely need to remove significant portions to all of the ship. Take it slow, and take pictures. Do some google and pinside searches, there are resources out there that will help, but it does take time.

Steps I found after a quick google search:
If you need to move the ship to get to the optos.

1). Remove the 6 screws to the black plate just under the ship and remove the plate.

2). On the right side of the ship (by the pop bumpers) remove the plastics and unscrew the one holding the bracket to the playfield.

3). Remove the screw on the left side and the 2 screws in the back.

4). Now you should be able to move the ship out of the way and get to the optos.

Best to have a magnetic screwdriver for this.

2 of my opto wires were switched around incorrectly on the board and that solved my issue. So check that first. I wish it was that easy for everyone.

Thanks Adydar. Very helpful.

Nah, switching the opto wires didn't help. I have J4 switched with J2 so that passing the lower opto activates the upper opto features. (Magnet, kickout, ship movement) Most of the newbie players, who are the ones who prefer my Star Trek to the Metallica, don't really notice there is a problem except in vengeance mode when the ship goes nuts.

So it's playable about 90% but gives free extra balls, more multiballs, and hits on the vengeance ship which inflates scores. Occasionally it locks the ball behind the drop target and it takes a while for it to get free. If i didn't have J4 and J2 switched, everything is just dead in the top opto and the game is basically unplayable, or at least not fun.

I'm thinking this may be my problem (during Vengeance multi-ball, if I hit the second ball into the lock, both it and the first ball stay locked until it times out). How did you know the optos were reversed? What should I look for? Thanks!

That is the problem that I had and the previous owner had before he sold it to me. After seeing threads on opto issues and bad boards and other tricks like twisting wires, I figured it had to be one of these issues.

After replacing board 1 underneath and putting the wires back into the board the exact same way they came off without checking them, the Veng. MB problem was was still not fixed. I realized soon after that that the line going to J3 and J4 were flip flopped. I corrected this and it Vengeance MB has worked ever since.

I assume the lines were flip flopped from the factory becuase both the previous owner for his ownership and me for my brief time of owning thought it was the boards and forgot to check the simple things first. It was instead a simple fix.

My J4 and J2 lines are together and my J1 and J3 are together coming fromthe optos, then they branch off to the board. Yellow tags guide you with J3 and J4 to the board, so just make sure J4's other line goes to J2 and J3's other line goes to j1 on the board. The board has J1-4 in small print.

My answer was a "Duh" on myself for not checking this first and I hope others can solve the problem this easily. Good luck.

Looks like Pinsider "shacklersrevenge" tweaked his optos to solve the problem. Perhaps he can help?

shacklersrevenge
Pinball master
2,585,9003
Gardner, MA

On the previous code, my Pro did this, but I also had the sticky magnet/opto problem. Once I tweaked/better potioned the optos , (especially the front optos) my magnet problem went away, as well as the vengeance flipper kill. New code and it's still gone...
I also think that if the opto holes on the metal guide rails were a tad bigger, it would fix the magnet problem for many, but maybe i'm wrong...

I checked my opto boards, and all the yellow tags say where the connectors are supposed to attach on each of the three boards (i.e.: J2 goes to J2 on Board 2, etc.). Do you suppose that the tags are wrong?

Probably not. Call Stern. Here is the forum topic that went over the issue below. Shacklersrevenge said he fixed his - PM maybe? Good luck.

https://pinside.com/pinball/forum/topic/stern-star-trek-multiball-magnet