Dammit, that left flipper was driving me crazy... It was buzzing like crazy in end of stroke (EOS) position. A loud hum that wouldn't stop. Every time I try to backhand it into the grave markers, I'd have to deal with that infernal buzzing.
Not today Satan!
This problem just started to happen in the past few months. Once it started to irritate me, I found a pinside thread. There were a few suggestions, and a lot of folks indicating it was "as designed" or "normal." Nope, It's not normal. It's irritating. My game is on about half volume, so you can hear (and feel the buzz.
A pinsider Bren-E (listed as inactive) put up a photo of a simple solution he had with an automotive gasket and a relocation of the spring washer. Here is the photo that links back to pinside. He cut a gasket (1 3/8" round with a 1/2" hole in the middle). Put the gasket against the coil stop where the spring washer was, and then relocate the spring washer to the other side coil mount.
I fixed the left flipper, and it worked well. In fact, it worked so well that I could now hear buzz on the right flipper, so I fixed that too. I made a short video.
I also got a GC and set a new record for Enter Sandman "Crank It Up" mode.