Most likely a problem with the EOS (End of Stroke) flipper switch - either dirty, bad or a broken wire. But I don't know if this game actually has an EOS switch or not, some of the DE games do and some don't. If it does have one The EOS switch (in these games, it operates differently in other generations and manufacturers games) tells the Solid State Flipper Board that the flipper is being held in the end of stroke position and if it gets knocked back by a ball to send another high-power pulse to the coil to resolve it. A good test is to find the EOS switch under the PF near the flipper mech and make sure the wires are not broken and that the switch gets closed (it is a normally open switch in these games) when the flipper is fully extended. Do this with the power off to make sure you don't get shocked. If that all looks good short across the switch using an alligator clip test lead and see if that resolves the problem. If it does try cleaning the switch with a piece of paper held between the contacts, if that still doesn't fix it replace the EOS switch. If you're not sure if it has an EOS switch after looking post a picture of the flipper mech from under the playfield or hopefully someone who knows for sure will chime in here.

This is a single winding flipper coil and it is controlled by a flipper control board.

More likely you have a fault on the flipper driver board.

That's the board. Try and find another machine from the same era and swap the board to confirm if that is where the problem is.

I wouldn't go replacing it. You could also send it away to one of the numerous repairers here and ask them to check it over.

These are pretty simple to repair. It's being said in numerous other threads that you are FAR better repairing the original board rather than replacing it with a modern board.

Yeah, no EOS switch on that. But the fuse for left holding (F4) looks burnt and may be blown - do you have any way to test it? If you have a meter and can pull the fuse (with game off) and test it on continuity (beep) that's what I would do next. If you don't have a way to test you could swap F2 and F4 and see if the problem moves to the right flipper.

Good eye sure looks burnt to me

You'll have to look up the correct value in the manual (should be on IPDB) but those look like Slo-Blo fuses and you usually won't find those in an automotive store. May have to order from one of the Pinball supply places or Great Plains, etc.

EDIT: Make sure you test those fuse clips like I mentioned earlier - they are a well known source of failure and if they are weak can cause excessive current flow, blown fuses, sporadic behavior, etc.

Marco specialties , Pinball Resource, Pinball life, those are good parts source. Amazon might be cheapest if u have prime, cause shipping is gonna kill ya if you just order fuses. Local electronic store like Frys electronics may might have them too .

I'd check all fuses for correct amp, someone before you wasn't too concerned about that stuff, and I'd think it's a good possibility it's the issue .

Try radio shack, they might have one , and there is one listed in Berlin ,NJ.

Under-fused for the circuit could definitely cause them to blow, as Joey said shipping will kill you if all you're ordering is fuses so hopefully someone local has them, even if they are close but not exact (4.5 amp or maybe even 4 amp) if they are local it would still be better than having to order the exact right ones.

I think your flipper problem lies in a different area. I have a Data East Robocop with a weak right hand flipper. I have not pulled my MPU to address the problem so I can't say this 100% yet. But my reference material says if there are flipper problems then a transistor on the MPU might be the culprit.

http://mirror2.ipdb.org/files/2356/Data_East_1991_Star_Trek_English_Manual_with_schematics.pdf

In my short time of owning my Robocop, I consider the following link to be the DE repair bible. Somewhere in the pages is the reference to that little transistor

EDIT: Incorrect link was linked when I posted. Now Corrected.

http://techniek.flipperwinkel.nl/desega/index2.htm#flip0

Over on the right hand side of this diagram/schematic is a small transistor a little to the left of the flipper ground relay. What I am reading says to replace this transistor. As I said, I have not attempted to replace mine yet, so no guarantees.

On my MPU board I have painted the offending transistor with some orange paint.

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I bought a 5 amp slow blow at menards in the electrical section once. It was about 4 times the price compared to pinball life, but got my game working the same day.

What's the rating of the ones you took out?

This is the schematic for the Star Wars flipper board. Part number 520-5033-00. Revision F. If this is the board you have then you need 3 amp fuses.

EDIT: My apologies. I said Star Wars instead of Star Trek. But both pins use the same flipper board. But I am confused about the 5amp fuses; Where in the manual did you see that? I can't find any reference to 5 amp fuses.

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In my first post to you I linked an incorrect manual. I have corrected that and will link it here, as well.

http://techniek.flipperwinkel.nl/desega/index2.htm#flip0

Section 3H talks about the solid state flippers and how they behave. And how they work with no EOS switch. Everything about the solid state flippers is in section 3h. If you have a flipper sticking in the up position it may be a bad diode.

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Sounds like it is definitely electrical since turning the game off drops the flipper - this is probably why the fuse was blown too. Are any of the LEDs on the board on when the flipper is stuck?

I would replace the diode, they are cheap and that's an easy fix just be sure to install the new one in the same polarity. As for it being a mechanical (flipper stop, etc.) problem I think that is very unlikely since you said that turning the game off drops the flipper. However the condition of the flipper rubber does not equate to the condition of the flipper mechanism itself, the rubber can be changed in 30 seconds or so without ever lifting the playfield and would usually be changed at least a few times between full rebuilds.

Ooof, I hope that wasn't all you needed. I love Marco but they kill you on shipping costs for small orders. I could mailed you a few (I have dozens) for free if that's all you need and you can still cancel your order. Feel free to PM me your address if so.

How did this post resolve? I can see the OP is still here posting.