Quoted from Eskaybee:
Just wanted to post this in case anyone else has similar Flipper Issues.
After about a week of play, my bottom left flipper started sticking in the up position. It wasnt the coil staying energized, but that the coil wouldnt not spring back to normal position. I put a tighter spring on the mech and that helped but every once in awhile it would stick especially when i'd cradle up and stage the flippers during play. I requested a whole new mech but Patrick Powers (stern - great support) wanted pics of the coil sleeve thinking it might have gotten the wrong one accidentally installed which was causing the shaft to stick. With the help of JJ at GEX (Great customer service on a weeknight!) he helped me identify what i needed to look for and to check out the coil stop as well.
<<<Insert time to laugh at me comment>>> after 13 years in this hobby i didnt know what the coil sleeve was or where to find the coil stop - i always thought the sleeve was the paper around the coil and you took that off to expose the coil and look at its 'sleeve' and thought the stop was the rubber that stops the flipper mech on the return - after JJ corrected me that the sleeve is in fact the plastic sleeve the coil goes in and out of and the stop is at the end of the coil (opposite) the wires, i embarrassingly unscrewed 2 screws (super easy) by the coil stop to investigate. <<<end laughing at me comment and back to troubleshooting topic>>>
I found that there was a big washer around the coil stop and it was warped to all hell. JJ was like wtf is a washer doing on a coil stop? Needless to say, we both agreed lets just remove it. This was approx a week ago and have not had a single problem since. Flippers work great and no more intermittent sticking. Hopefully someone gets use out of this post, or at the very least gets a good laugh at what i thought a coil sleeve was or maybe finds out what a coil sleeve and stop is like i didnt lol now at least i know what is involved when people talk about cleaning coil sleeves and/or filing coil stops. Its not replacing paper or filing a rubber stop
Isn't that "washer" a spring of sorts to help with vibration/keeping the coil tight? Pretty sure my Sterns (all two of them...) have had those on each coil stop, and I'm surprised the distro wasn't familiar.
EDIT: yes, I believe you're referencing the "spring washer" part 269-5002-00 per my Avatar manual, same washers were on my LOTR. http://www.marcospecialties.com/pinball-parts/269-5002-00