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BK2K upper flipper flutter.

DanLewell

DanLewell

Registered
10 Years
Joined
Jul 21, 2011
Messages
1,049
Location
Northampton, UK
Hi,

I've got a problem with my BK2K. The upper flipper won't hold up. It just flutters while the lower flipper holds fine.

Looking at the wiring I think it works like this, there is a switch on the lower flipper mechanism that triggers the top flipper, not on the flipper button as I expected first of all. Why didn't they just wire both flippers to the flipper button?

Anyway, there is another switch which is normally closed that becomes open when the upper flipper fires. I am guessing this switches from high voltage to low voltage. It looks like everything is moving freely and the switches look to open and close without any issues, but the top flipper flutters.

The thing that looks really out of place is a jumper wire with red sleeving that is attached to the open side of this last switch but doesn't connect to anything else, what on earth is that for?

Any advice of where to look next would be gratefully received.

Cheers,
Dan.

image.jpg
 
I can't see a capacitor lying around anywhere and it was working ok before but if there's supposed to be one there I'll happily put one in.

Any idea what spec capacitor it's supposed to be and where it's supposed to connect to?

Any photos of that area from your BK2K would be useful.

Cheers
 
Not sure if the lack of capacitor is causing your flutter but theres supposed to be one there to make the switch contacts last longer ( i think! ). I'll let the more experienced pinheads on here jump in in 3....2....1.....
 
Yep, it's normally a short in the coil that causes fluttering but not always. Poor EOS switch can have the same effect. If you can figure out how that red wire should be connected it make help resolve it. Try comparing it to one of the other flippers in the game...
 
Hi, Dan

I'd suspect that the secondary winding of the upper flipper coil has failed; possibly the (thinner) wire has broken off one of the terminals. On the older type flipper unit, the End of Stroke switch opens to cut the high-power primary winding out of the circuit, leaving the lower-rated secondary winding to hold the flipper raised. If the secondary winding isn't working, the flipper falls back, switching the primary winding on again, and causing the flipper to chatter.

Looking at the picture, is the coil an 'FL 11722'?. If so, it's the wrong rating for Black Knight 2000 anyway (too weak), so you'd be best changing it for an FL 11630, and fitting a new EoS switch, with capacitor. If you have a manual for the game, the listing for flipper assemblies will include the capacitor; I think it's 2.2 microfarad, 250 volt. WMS games with parallel-wound flipper coils (F-14 through to Hurricane) use a capacitor on each EoS switch to reduce sparking across the contacts.
 
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OK, I think all that makes sense. I'll have another look tonight once the kids are in bed and see if I can get it working. I'll let you all know how I get on.

Cheers.
 
another thought? How do I test to see if the coil is knackered. I can look to see if there is an obvious break in the wire where I can see it, but is it possible to test for a break under the coil wrapper where I cant see it?

I've got a multimeter but never really known what I'm doing with it. I can make it beep when checking for continuity, and get it to tell me the voltage of a battery but that's about it.
 
DanLewell said:
another thought? How do I test to see if the coil is knackered. I can look to see if there is an obvious break in the wire where I can see it, but is it possible to test for a break under the coil wrapper where I cant see it?

I've got a multimeter but never really known what I'm doing with it. I can make it beep when checking for continuity, and get it to tell me the voltage of a battery but that's about it.
Click to expand...

See if that makes any sense :)
 
Thanks everyone. It was indeed a break in the thin coil wire.
I managed to unwrap a bit more on that wire and resolder it so it's back up and running again.
 
DanLewell said:
Thanks everyone. It was indeed a break in the thin coil wire.
I managed to unwrap a bit more on that wire and resolder it so it's back up and running again.
Click to expand...


Nice work,was jsut catching up on posts and was gonna comment,in fact I fixed a game at the weekend with the same problem.That turned out to be a cable off the switch stack.
When I have had this in the past it has been a connection problem(ie cable off or switch contacts booloxed),or as @GrizZ has said cable winding off at the solenoid.
Normally one turn unwound then scrape off the laquer then reattach,and then it can last a long time after that.
can be a problem if winding is from underneath the coil wrap,tho bending that lug at right angles thus making it nearer to broken winding,and then reattaching works.

To test coil,put your meter on the ohms setting(the one that looks a bit like a headphone symbol),if autoranging meter all fine,if not put onn 200 ohms setting.Them put black lead on one end,and red lead on the other and see resistance - if close to zero ohms it is a dead short so coil fooked,if not it will read relevant for the coil 20 ohms or less as a mega vague ball park figure see here http://www.pinballmedic.net/coil_chart.html#gottlieb_relay_coil_turns_resistance_chart

Bear in mind if flipper there may be three windings,so middle to inner will be one value,middle to outer connection will be another.
In this case one will be a few ohms,the other will be a few hundred ohms(the holding part of the flipper)
 
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