Getting a high score, but tilting the last ball:

Worf: You are without honor! You are an honorable player!

Make up your mind already!

This sounds like the same problem I had.

The playfield slides and pivots on two metal pins screwed into the cabinet. The motion of rotating the playfield up eventually unscrewed the right pin from the side of the cabinet. You need to screw this pin back into the cabinet.

I only noticed it on mine because I had the game in switch test mode when I lifted the playfield, and I could hear a switch activate as the pivot pin contacted the switch. It hadn't unscrewed enough by that point to break the switch.

On your game, this may have also hit the wires on the upper right flipper causing a short and a fuse to blow on the fliptronics board, so you might want to check this out.

"U.S.S. ENTERPRISE MISSIONS Shoot START MISSION to Behind Each Mission. Shoot Flashing Emblems Complete Missions." should be "Begin Each Mission" and "Emblems to Complete Missions" and a missing colon after MISSIONS. Maybe the fourth times a charm?

I thought that worn area by the right emblem insert was caused by the ball dropping onto the playfield after launching. Maybe the heat from the bulb contributed to it. Mine is like that too.

When I bought my game it had the Cliffy one without the holes, but it wouldn't stay in place even after trying to bend the metal to make it hold better. I felt like it would/could slide into the targets and possibly make the target switches get stuck closed, so I ended up drilling a hole in it and installing a wood screw. Now it's held in place. I didn't want to have a malfunction during a tournament it was in.

I don't know about spotlights but I have cool white LED bulbs in the GI and bright ones under the slingshots aimed toward the center with translucent Titan rings. These light the area above the flippers where it matters the most. I also have a white LED under the Klingon ship wing aimed toward the center of the playfield, but hidden from the direct view from the player's perspective. I believe these bulbs under the wings were intended to light the playfield a bit, but I see other removing or rotating the ship and putting darker lights under there.

The Operations Manual shows the clear plastic piece (03-8630 Guide, Actuator) on the outside of the switch, and it's positioned upward to prevent the switch lever from being pushed sideways (toward the left side of the cabinet). I don't know why, but it seems to end up positioned downward, maybe because someone thinks it's supposed to shield the wires. When I bought mine it was positioned downward and my switch lever had a lot of lateral play in it just like pcprogramer's switch. The shape of the tab on the drop target tends to push the lever sideways, so I believe this plastic should be placed on the outside of the switch (as shown in the diagram).

The switch was acting flaky. Data would say, "lock is lit" at random times, like when I'd use the flippers before ball launch. I replaced the switch and reused the lever after bending it where it connects to the switch to make it tighter. It's been working well since then.

My left cannon laser stopped working and I noticed there was a transistor soldered and heat shrunk inline with the wires. This transistor would get very hot when the cannon motor was on (when the laser should be on). I'm not sure if this was a problem with the transistor or the laser shorted out. I did accidentally let the cannon rod fire into the laser when I was working on it, so the laser itself may have been damaged. I just ended up removing both lasers. The cannon modes are too easy with the lasers IMHO, but I'm curious about how/why the lasers fail.

Check the leads on the big blue resistors on the trough opto board. It's a common problem that the heat and vibration cause the metal leads to break. It will still be contacting, but vibrations (like from balls draining, flippers, etc.) will momentarily break the contact to the board and trigger the opto switch.

What do you mean by "lost"? Presumably you know where the ball is! Does it go into one of the playfield scoops, then it doesn't kick a ball up?

You may have a loose screw or piece of broken plastic in the subway preventing the ball from rolling down to one of the up kickers. I had a plastic piece of the Alpha Ramp break and fall into the subway and it caused this problem.

I just tried it and this worked! This is the first explanation I've read on when this lock lights. Seems like it's not worth going for just to light the lock unless you have plunge into lock turned off. Turning off plunge into lock and holodeck makes the game a bit more challenging.

And check that a wire didn't come loose from one of the diverter coils.

Now that he's hooked, turn off free play, lol.

When it gets stuck up gently turn off the game. If it stays up, then it's a mechanical issue. If it goes down then it's an electrical issue.

Sounds like a flaky opto under the start mission hole. If that opto doesn't register, the ball travels down the subway and hits the opto under the rank hole, so the game thinks the ball fell through the rank hole. A similar thing happens if you fall in the neutral zone hole without hitting a stand up target. The ball rolls down the subway and the game thinks the ball fell in the rank hole.

Also, if you have a weak unregulated 12 volt supply it will cause opto issues. This seems to happen more during multiballs. If a cannon is rotating it will drive the opto voltage down because they use the same 12 volt unregulated circuit.

Clean the diverter mechanisms. Just replace all the optos in the subway VUKs (4, 2, 2). You can get them cheap. Get new trough opto boards from Great Lakes Modular if you can. Check all your voltages at the test points on the power board in attract mode and while playing or doing tests. Test all the 5 large capacitors on the power board and the smaller capacitors. Test the 5 bridge rectifiers. Do the tie-back mod on the wire on the drop target coil. Rebuild all the flippers including new flipper bats. Rebuild the slingshot mechs and pop bumpers if they are weak. Go ahead and resolder all the solder joints on all the solenoids. Replace all the playfield rubbers. Check for cracks on the ramp plastics where the ball hits when entering. Either replace the ramps if cracked/broken or install metal ramp protectors. Install a set of plastics protectors under the plastics around the playfield. Install LEDs if you want. Some of the bulb holders (like for the shields) get loose solder joints, so you may have to clean and resolder them if the lights are flaky.

I'm not sure where it's hitting the metal backstop, but one thing to check is that the plunged ball isn't hitting the habit trail above it that leads back to the right inlane. If the top habit trail is not aligned directly on top of the bottom one it will interfere with the ball and slow it down enough that it doesn't reach the hole.