Left Flipper on Gottlieb wipeout gone crazy

[deep six]

I have a heap of pins to get going but figured I should start with the easiest one first.
Starting with my Gottlieb Wipeout
My left flipper is flipping, but not in a good way, it oscillates crazy up and down when you hold the button in.
My first thought was that the coil was bad and simply needs replacing, however assumptions are not the best way to diagnose problems so thought I would throw this one out there for a second and maybe third opinion.
I did check the flipper switch, gave it a light file and cleaned it, seemed to make the flipper work a little better momentarily but was soon back to how it was.
Thanks in advance for any suggestions

[Steevsee]

Check/clean the EOS (End of Stroke) switch on the flipper assembly.

[deep six]

Thanks mate, I didn't realise there was such a thing but learning as I go.
Is this a clean with solvent thing or clean with light sand or file??

[48]

Sounds like the hold winding on the coil is not working Check as per Stevesee and also cheek the coil winding ( the thin wire)
for open cct

[Steevsee]

Thanks mate, I didn't realise there was such a thing but learning as I go.
Is this a clean with solvent thing or clean with light sand or file??

Many EOS contacts are tungsten and need to be filed with a metal file, but I'm not 100% sure if Gottlieb system 3 are tungsten or not.

Maybe try cleaning with solvent first and a light file to see if it makes any noticeable difference.

[ajlaird]

If the EOS contact is pitted you are better off replacing it.

[beaky]

Sounds like the hold winding on the coil is not working Check as per Stevesee and also cheek the coil winding ( the thin wire)
for open cct

I agree on this one, the coil that is connected to the EOS is working, but the hold coil is not. flipper goes up, opens eos, then there is no hold coil working to keep it up, so as soon as the eos opens the flipper drops down and the eos closes so the coil energises again and then goes back up, opens eos, flipper drops and so on. 

[pinnies4me]

The EOS on a System 3 game like all Gottlieb ss games are tungsten, so as they carry the high power will degrade and need filing or replacement.

If there's still a decent amount of the contact there (ie not worn right down), file the contacts with a small file like you would use for an old set of points in a car. I use a points file in fact. Get both sides shiny and flat, and then re-seat, ensuring that when the flipper is in the rest position, there is good contact between the points, and that when the flipper gets almost to the end of its stroke, there is say a 1 mm gap. Even if this is not the actual problem you'll improve the flippers by cleaning the EOS points anyway.

If the points are in terrible condition, you should replace the assembly - http://www.rtbb.com.au/catalog/product_info.php?cPath=218_70&products_id=1070

Depending on how long ago it was done, it might be worth a flipper rebuild - http://www.rtbb.com.au/catalog/product_info.php?cPath=218_70&products_id=1268

Nothing improves a game than a freshly rebuilt flipper set, I do it on every game I buy, best $40.00 investment in playability.

Of course yours could also have a dodgy coil as you originally mentioned.

[Mr Pinbologist]

Sounds like the hold winding on the coil is not working Check as per Stevesee and also cheek the coil winding ( the thin wire)
for open cct

I agree on this one, the coil that is connected to the EOS is working, but the hold coil is not. flipper goes up, opens eos, then there is no hold coil working to keep it up, so as soon as the eos opens the flipper drops down and the eos closes so the coil energises again and then goes back up, opens eos, flipper drops and so on. 

+1. Check the coil. hold coil will be open circuit.

[deep six]

Many thanks for all the replies on this one, I appreciate all the tips, sorry for the slow reply, had to pack up some orders to go out.
I just lifted up the bonnet on the Gottlieb, located the EOS switch, gave it a light file with an automotive points file then cleaned with some metho. Checked the coil for open circuit, wasn't sure which was the primary winding and secondary winding but got continuity through all 3 points so guessing the windings are intact.
Started up the machine but still got the crazy flipper action. Not sure where to go from here, maybe time for a new coil???