Flipper going mad on my Mario Bros - Flipper going mad! Help please ;)

[Mark]

Hi all,
I'm hoping someone can help with a problem with my Mario Bros.......... the right flipper died (I didnt see what happened as I wasnt there), but when I went to investigate today I saw the fuse for the right flipper had blown...

Anyway, I hoped it would simply be a case of replacing the fuse, but unfortunately there is a further problem. When the right flipper is activated, it goes mad, ie; with button held down it fires again and again really quickly rather than being held in the "up" position, which is obviously what caused the fuse to blow!

Ive had a look and nothing seems obviously wrong visually, but it has been ages since I've fixed a pinball machine I'm a bit stuck on where to start. Any advice on what it could be?

Thanks in advance, Mark.

 

[Carl Spiby]

Do Gottlieb coils have a low power (hold) winding? That could be broken or disconnected, or it could just be a dirty eos switch.

 

[astyy]

What Carl said. Mine did that on a Bally when the low power coil on the flipper solenoid failed (relevant if the coil has 3 tabs) - I found advice on the web searching for 'machine gunning'!

 

[Mark]

Ahhhh, "machine gunning" sounds like a good description - I was going to say it was like a bee's wings, but "machine gunning" sounds more manly -lol.

I'll check whether it has 3 tags when I go out there later. I'll also run a business card between the contacts to make sure they are clean.

I suppose if it is the windings on the coil, a new coil would be needed. Will report back when I've had another look.

Cheers, Mark.

 

[chris b]

Does the coil have diodes on it mark ?

 

[Jay Walker]

Hi, Mark,

I don't think that Gottlieb ever went to the trouble and expense of developing a 'Solid State' flipper system like WMS 'FlipTronic', and stayed with a 'conventional' high-current switching unit.

The term I've always heard and used is 'chattering' - it can happen to the slingshot unit too, on some games, if the contacts are too close together.

As already stated, the coils' secondary 'hold' winding is probably open circuit. You may be able to spot if it's broken off near one of the terminals. It may be feasible to unwind a single turn of the winding, clean off the insulating lacquer and re-attach to the terminal (if it's the outermost end of the winding. Hopefully the fuse(s) prevented the primary winding from overheating.

 

[stoptap]

That game is greatly enhanced by disconnecting all the flippers.

 

[Mark]

Hi guys, I've not had a chance to look into this yet but will have a look later today It does have 3 connections to the coil, and visually nothing was obviously wrong when I had a quick look earlier. The coil looks quite new (I think it was replaced as part of a service visit within the last year), but I guess a winding could still be broken. Will check shortly and report back.....

Ha ha, good point Andrew, however although it is not the deepest game in the world when I sell anything else on eBay, if anyone can see the SMB in the picture, I always get questions about whether it is for sale, so it much be popular with some people
Thanks again, Mark

 

[Mark]

Hi all, right I had a few minutes so I got my meter out to check the working coil (left) against the machine-gunning coil (right).

Measuring across the two outer tags, the left reads around 200Ohm (measured either way) however the right coil reads around 10Ohms (measured either way.

Does this mean the coil is duff? It looked like the wires were connected onto the tags on both coils, and the contacts were clean.

THanks in advance, Mark.

 

[Jay Walker]

Yes, it looks that way, Mark. The coil type and the diodes will have some influence, though. I don't know if Gottlieb were using the older 'serial' wound coils or the more modern 'parallel' ones at the time (I'd guess serial), but the lower reading for the faulty side points to it just being the power winding. With either type, with the EoS switch open (put some plastic or paper between the contacts), a defective hold winding would show an open-circuit when measured in one direction, and simply the 'forward' resistance of the diode(s) when measured in the other.

The winding type can be seen by looking closely at the terminals - serial coils have both the thicker power winding and the thin hold winding connected together on the centre terminals, while parallel ones have both windings at the 'live' terminal, with the power winding on its own at the centre tag (diode excepted).

 

[Mark]

Thanks Jay! So it looks like I need a new coil........ I'll see if I can find one somewhere

Thanks again, Mark

 

[Mark]

I've ordered a new coil and will report back once fitted
Cheers, Mark.