Weird flipper sticking problem on Doctor Who...help!?!

Vectorman

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Guys,

I'm out of ideas for this Doctor Who. Never seen anything like this.

The right flipper sticks up sometimes. Seems like it is slightly held magnetically. Turning the game off doesn't immediately release it. But eventually it does.

I have replaced the entire flipper assembly - everything. I tried rebuilding the fliptronic board with all new components - didn't help. I just tried installing a NEW replacement Fliptronic board and now BOTH left and right flippers stick like this.

I don't think it is mechanical. when you move the flippers by hand they are both very loose and non-sticky. But flipping them electronically causes them to stick.

What is causing this!!!?!?!?!?!?! HELP!!!!?!?!?!

Thanks,
John
 
Did you check your coil sleeves and the end stop?

Sometimes you get a chip in the coil sleeve. Or the end stop (that the plunger repeatedly smashes) gets peened over, and a "booger" can snag the slug.

I'd suggest taking the coil apart and looking at all the pieces.

It isn't clear what you mean when you say "I replaced the entire flipper assembly" - did you mean the entire plate, all the ends, the coil, etc?
 
Asking to be specific about something in regard to assistance with diagnostics is perfectly reasonable.
 
If the flippers stay up when the main power switch is turned off, it's almost certainly a mechanical problem.

There are lots of little details to a flipper rebuild that need to be attended to if you want correct operation with every flip. One of the most commonly overlooked is the vertical position of the crank on the flipper shaft. If it's set too low or too high, there will be binding. I'd check that first. Also it's important to get the crank sufficiently tight on the shaft, otherwise it will slip.

Another common "gotcha": In the 90s, WMS used two different coil stops, and two different plunger/link assemblies. A mismatch between these parts can also cause binding... in particular, when the shorter coil stop is used with the shorter plunger.

Lots of other possibilites, but there's a start.
 
Thanks for all the tips. Some more info. When I say I replaced the entire flipper assembly, I mean I bought the marco specialties replacement flipper assembly - everything is included:


I have noticed the marco's parts have been lower and lower quality as time goes on. Maybe they used the wrong plunger and link with the wrong coil stop?
 
I have noticed the marco's parts have been lower and lower quality as time goes on. Maybe they used the wrong plunger and link with the wrong coil stop?

I think they are doing the best they can with what's available.

Back when WMS was still in the pinball biz, the rebuild kits were a great solution. The kits were assembled by Williams with the same OEM parts they were putting in new games, so the quality level was very high, and they were quite economical. Also, lots of location games would have ragged-out flipper assemblies from heavy play... so it made sense to shotgun replace most of the parts.

Now that the parts are all aftermarket, with variable quality... and most games are seeing much lighter play, having been in home use or perhaps an arcade bar for the past decade or more... I think it makes more sense to just replace what's actually needed, and leave the rest alone.

I'm not saying you should put all your old parts back, but I hope you didn't trash them, because they may still be useful. In particular, if your old coil stops look decent, you might try swapping those back in, and double-check everything else while you're in there.
 
Sounds like a magnetized coil stop or plunger issue. Try swapping in new plungers and stops, even new ones can get magnetized quick. Also make sure the EOS switch wiring isn't shorted to the coil lug.
 
Thanks for all the tips. Some more info. When I say I replaced the entire flipper assembly, I mean I bought the marco specialties replacement flipper assembly - everything is included:


I have noticed the marco's parts have been lower and lower quality as time goes on. Maybe they used the wrong plunger and link with the wrong coil stop?
Or it could be something with the level set height for the flipper bat.

Check with a feeler gauge what the working (non-sticking) one's height off the playfield is, and then check the "sticking" one's height. If there is a difference, fix that.

Look for any burrs on the shaft in the bearing areas. If there are any, gently remove them using crocus cloth or a fine file until they are smooth, or replace the entire flipper bat assembly.
 
Quick update for all of you who chimed in to help. Thanks so much for all the ideas - you are very appreciated.

It is now fixed. The left flipper that just started acting up was caused by a cabinet switch that was out of adjustment - had come slightly loose. Easy fix.

The right flipper that plagued me turned out to be the magnetism issue DEANIATLY suggested. I think the P&L and coil stop (which were both almost new) had somehow gotten magnetized. The sticking would continue after turning the game off. and the flipper moved very freely otherwise. The gap was already correct (although that was an excellent tip - that gap definitely needs to be exactly right). I tried just swapping (another) new coil stop and P&L and the problem has now vanished. Praise God...my customers will be glad to have this game working again.

I sometimes get a mental block where I just don't want to deal with a problem, even thought it's a <1 hour fix. This game has sat out of order for like 6 months because I just didn't know what to do and didn't feel like dealing with it. So thanks again.

Another example - I've got a RFM that the computer went out on, and I ordered and bought a new replacement. But I just can't seem to summon the will to go and do the swap / tackle the learning curve. So it's been out of order for almost 2 years now...lol. Anyone want to come do the computer swap for me? I think the problem is that I need to swap the monitor for a flat screen at the same time and I just don't want to deal with it.

Thanks again guys!!!! until next time.....

John "vectorman"
 
I think they are doing the best they can with what's available.

Back when WMS was still in the pinball biz, the rebuild kits were a great solution. The kits were assembled by Williams with the same OEM parts they were putting in new games, so the quality level was very high, and they were quite economical. Also, lots of location games would have ragged-out flipper assemblies from heavy play... so it made sense to shotgun replace most of the parts.

Now that the parts are all aftermarket, with variable quality... and most games are seeing much lighter play, having been in home use or perhaps an arcade bar for the past decade or more... I think it makes more sense to just replace what's actually needed, and leave the rest alone.

I'm not saying you should put all your old parts back, but I hope you didn't trash them, because they may still be useful. In particular, if your old coil stops look decent, you might try swapping those back in, and double-check everything else while you're in there.
You are so correct about this. It's true in so many areas. I'm in the process of "restoring" about 300 video games for my next expansion. I used to just automatically rebuild every monitor and replace every flyback, replace all the power supplies etc with new ones. Not anymore. New parts have gotten so "sucky" that I have found myself re-using old flybacks I removed in the past that are still good. I'm rebuilding old peter chou switchers because I can't find good new ones anymore. And rebuilding and using original power supplies from old games like Exidy, Stern, Williams, etc...rather than putting in switchers. These old things made in the 70s and 80s were so much higher quality.
 
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