If you manually ground it, nothing else is running. I'd suspect power loss. Are all coils weak ?

LTG : )™

Is the mechanism working smoothly? Is there any binding? Did you change the coil sleeve, etc? The high power coil only goes for a very short time and your grounding is probably longer than the CPU applies power, so, my hunch is that something mechanically is stealing energy.

Also, getting power readings at various points and at the coils would be helpful. You should not have to up the coils power; mine works just fine with standard coils, but I did rebuild mine when I got it with a new plunger, sleeve, spring and grommet and it's been fine.

Marc

Double check that the transistor you are grounding is the right value; a friend of mine had a vuk acting weak, and it turned out that a previous owner had replaced the transistor during a repair with a lower current one, hence lower drive to the coil.

It's not too short on everyone else's game. Something is different in your house; we just don't know what it is yet.

Really good idea, but the OP had indicated a different driver board also had the issue. Odds are that two different driver boards wouldn't have the wrong transistor. I think it's time to get the meter out and measure voltage.

I will measure my TOM tomorrow after work and see what my voltage is at the coils.

Trap door test mode is a bad test. That will exhibit the same behavior you describe: in test mode, it only pops the trap door up a little and drops it down. The only way to really test the trap door is during a game. (Maybe take the glass off unless you're a good shot

Is your issue only in test mode, or in gameplay? If it's in test mode, mine does it too... In game play it's 100% fine. It's a bug in the diagnostics for this game.

Marc

The test mode behavior you describe is exactly the same on my machine. As for why your machine isn't working in gameplay, I am just not sure what's up.

Marc

Remove the spring, and report back how it works.....

Hey

Had this problem on my TOM. It's been years so I'll try to explain as clearly as I can. The coil stop broke off on mine and I put a entire new steel bracket in. When I went to test it acted like yours does in that it would only lift a tiny bit then go back down. There is an adjustment down below on the trap door piece with a screw or possibly a nut (this is where it gets fuzzy) that needs to be adjusted. It allows you to adjust the piece up or down. There is a sweet spot that you need to hit. Not enough and you won't get the power to lift. It was working prior to me changing the bracket so I knew it was just an adjustment problem. As it turned out that's all it was. Concentrate your efforts there and I'm sure you will get it working. I wish I could explain more clearly...It's just been 5 years or more. Good luck.

Good luck Bill. Wish I was closer so I could help out. I know if I could see it I would be able to remember better.

Go to your first post, hit the edit thingy on the top line with quote, report, ignore, and then you can alter the topic line.

LTG : )™

I am glad you found a fix. It's a little puzzling as the stock coil works for the rest of us. I wish I understood what's going on, but nevertheless, enjoy your fixed TOM!

Marc

I had the same problem when I replaced the bracket housing. i upgraded to the same coil and the problem was solved.

I had the exact same problem and used the same solution and all is working great now. Thanks all for the ideas, and its frustrating that Marco doesn't disclose this (or have a freakin clue about it). See my issue and solution here: https://pinside.com/pinball/forum/topic/theatre-of-magic-tom-trap-door-failure

interesting, would of never occurred to me to mess with that piece. I sent mantis a message asking about that, didn't make sense since both assemblies looked almost identical. I still might just grab a slightly more powerful coil just in case.

I wrote Kerry the guy who made these new assemblies and what he said makes sense. The old assemblies are made out of plated steel, a more ferrous metal, which in conjunction with the coil adds to the electromagnetism when its energized. The new ones are made out of stainless steel a tougher material in general, but not ferrous. i.e. why you might need a stronger coil. I've found that even coils of the same model have a different resistance (which might of played a role on your machine?), usually not off by much.

I looked for the adjustment you were referring to, was thinking maybe the trap door part could be moved up or down. Wasn't able to find anything though.

In case you googled "Theatre of Magic trapdoor issues" and found this thread, Allow me to assure you that:

- if you had a broken coil stop under the trapdoor
- and replaced it with the excellent Mantis replcement part
- and then found that the coil wasn't strong enough to raise the trapdoor

...then I'm happy to confirm what others have reported: upgrading the trapdoor raise coil from A-20099 to a yellow flipper coil (FL-11753 or A-15943) solved it. I don't think it's necessary to clip out the diodes in the replacement coil but I did while troubleshooting a separate problem after reassembly. (I forgot during reassembly that the trapdoor eject popper needs two springs, not just one.)

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