(Topic ID: 125295)

Tech: Twister not detecting Ball on Magnet


By MrDo

4 years ago



Topic Stats

  • 29 posts
  • 11 Pinsiders participating
  • Latest reply 1 year ago by woody6092
  • Topic is favorited by 1 Pinsider

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#1 4 years ago

I'm standing at the finish line on bringing a Sega Twister back to life and I need a little help...

Problem:
The magnets do not sense when a ball is on them. They work well (hold and throw), but the related switches (25, 32) never register as closed. The magnet board appears to reset properly (2 blink code) as described in the manual. No fuses blow.

What's been done:
Lots.
*Power Driver Board replaced with a Rottendog
*Magnet board replaced (Service Bulletin already complete on replacement board from Marco)
*Upgraded game ROMS to 4.05

Thanks for any help! A lot more has been done in trying to bring this machine back to life, I only listed the major things that may apply.

#2 4 years ago

Did you replace the the flight sensor?http://www.marcospecialties.com/pinball-parts/545-5705-00

#3 4 years ago
Quoted from pinsrus:

Did you replace the the flight sensor?http://www.marcospecialties.com/pinball-parts/545-5705-00

I ordered one of those but have not installed it yet. How would that affect either magnet when it is nowhere near them?

I'm not sure the magnets actually sense when a ball is on them, but they might.

#4 4 years ago

When the ball rolls onto the disk I believe the flight sensor is what activates the magnets at certain times in the game.. it sounds like his magnets are working in multi ball so that Could possibly be the case. It's just simply not registering the ball. I'm not a tech by any means and twister is my arch enemy. Had issues for years with one

#5 4 years ago

Goodluck

#6 4 years ago

The "sensor flight" or the part you linked are the wings that are attached to the chase ball which is mounted on top the ramp in the right of this photo and originally came made out of cardboard I believe. If I get some time later I will look at mine and see if there are indeed any switches that detect the ball on the magnet.

image-21.jpg

#7 4 years ago

Lol I do believe you are correct. It has nothing to do with any thing, it's for aesthetic only..

#8 4 years ago

I may get around to putting mine on one of these days. The old one is worse for the wear. It about one of the only parts you can get for this machine anymore.

#9 4 years ago

Ya I hear you, I sold mine as a project with that part I never put on as well lol.. I ended up purchasing another as it was for the wife. Luckily no broken plastics and everything is in decent shape.

#10 4 years ago

It must have some circuit that detects the ball on the center magnet because that is the skill shot when you plunge the ball. I am looking into it now.

#11 4 years ago

Yes, you have to be basically dead on for the mag to activate the skill shot.

#12 4 years ago

Reading the theory of operation of the magnet board in the manual is like rocket science, but basically the circuits that detect the ball on both magnets are contained on the board and it is a changing frequency when the ball hits the magnet that triggers these on board switches. There are no more wires to the magnet itself, but there are three going out to the switch matrix at pins 5, 7, and 9. I would test to see if maybe the ball does catch during a skill shot and if it scores the reward. If not, the board, board connector, or wiring thru the matrix may have a problem.

#13 4 years ago

Be suspicious of the magnet processor rom chip if it came from Marco. Many (all?) are known to be defective. Apparently Stern "lost" the file and can't burn new roms so Marco doesn't have any. I got one from Rompingirl on Ebay.

#14 4 years ago
Quoted from sbmania:

Be suspicious of the magnet processor rom chip if it came from Marco. Many (all?) are known to be defective. Apparently Stern "lost" the file and can't burn new roms so Marco doesn't have any. I got one from Rompingirl on Ebay.

Thank you SO much... I actually have tried TWO, but both appear to be from Marco, based on the handwriting on the sticker.

Thanks also to O-din! The ball gets caught for the skill shot, the magnet grabs it (and eventually throws it), but the skill shot does not get awarded. I agree, the manual is absolutely ridiculous where that explanation is concerned!

Neither magnet registers (as a switch) in any of the tests. Generic Switch test nor Twister specific tests.

#15 4 years ago
Quoted from MrDo:

I agree, the manual is absolutely ridiculous where that explanation is concerned!

To say the least! That rom info was a good tip and I'm really not too sure about the data exchange between the magnet board and the cpu but I would still check the three wire matrix connector for continuity to the next switches in line. Mine has always worked, but I will know what to look for if it ever fails.

Good luck!

2 weeks later
#16 4 years ago

Ok.. to follow up...

sbmania nailed it! Not one, but TWO magnet chips were bad from Marco! Ordered the one from "Rompingirl" on Ebay and the issue was instantly resolved!

Thanks again for the help guys!

-M

#17 4 years ago

im glad when i can help bring a pin back to life.
Dave Astill
rompingirl on ebay

1 year later
#18 2 years ago

Glad I found this thread, just installed the Dave Astill/rompingirl chip and Twister is fixed. Thanks

#19 2 years ago

That chip in the twister magnet board is a PIC/GAL chip. If I remember right, once they're done programming, they make it so you can't get the code off them because it burns off the connection to the leg. So someone must have either had one that was still readable or they reconnected that pin to make it readable so they could make more. I remember when I had a Twister where this was out (seems like virtually all of them are!) and this was the biggest pain.

1 year later
#20 1 year ago

ordered one worth a shot.

1 month later
#21 1 year ago

Hopefully someone reads this before the end of the year.....the magnets on mine were working and then just stopped. No skill shot or loop catch on either magnet. So am I to assume this magnet chip from on Ebay is the fix?

#22 1 year ago
Quoted from mainelycoasters:

ordered one worth a shot.

Any success? Both magnets on mine were working great until a few days ago, now neither work; nor does the spinner.

#23 1 year ago
Quoted from woody6092:

Any success? Both magnets on mine were working great until a few days ago, now neither work; nor does the spinner.

Did you check your fuses yet with a multimeter?

#24 1 year ago
Quoted from brainmegaphone:

Did you check your fuses yet with a multimeter?

Haven’t even put it on yet but it sure looks blown.

232DB83A-9450-4E9B-BDC4-348C4EF2981D (resized).jpeg

#25 1 year ago

That might be your issue. Check the service bulletin for Twister below if it keeps blowing every few days.

http://arcarc.xmission.com/Pinball/Stern%20Service%20Bulletins/sb/sb91.pdf

#26 1 year ago
Quoted from brainmegaphone:

That might be your issue. Check the service bulletin for Twister below if it keeps blowing every few days.
http://arcarc.xmission.com/Pinball/Stern%20Service%20Bulletins/sb/sb91.pdf

Brainmegaphone...thank you so much for the information. I'll try the fuse replacement and go from there, and keep you posted. Thanks!!!

#27 1 year ago

Of all the toys on pinballs this has to be the worst design ever for reliability.

#28 1 year ago

my rear magnet still not going but machine has other issues I am focused on which is flippers go weak at times in the game, seams to happen after a deep long chase multiball, I have not noticed it in others and happens after a few jackpots. the lights flash and flippers go weak as do all coils balls drain and then locks up. no fuses will be blown and game will after a restart boot right up and play normal.

#29 1 year ago
Quoted from brainmegaphone:

That might be your issue. Check the service bulletin for Twister below if it keeps blowing every few days.
http://arcarc.xmission.com/Pinball/Stern%20Service%20Bulletins/sb/sb91.pdf

BLEW the new fuse right off the bat!!! First skill shot the magnet grabbed it for about 2 seconds and then it was done....doing the SP91 service this weekend!

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