I have a similar issue, your pics didn't post for some reason. I can check out that wire to see if I have an answer. Re-seat the connectors on the solenoid driver board and check resistance through the lines to and from the flippers on that board, like a blue, green, red and orange wires. If your getting more then say 1 Ohm that could be a cause for intermitant flippers (Should be 0.1 to 0.4). It's frustrating, what I did and am doing... New flipper switches, new enable relay from Digikey, brand new driver board pins, capacitors, did the sound board while I was at it. Flipper coils, EOS switches. I'm still working on replacing the molex female ends of the connectors.

If I still have a flipper problem after all that... time for a BIG fire!

Oh the flipper enable relay is supposed to trip on/off at start up.

Agreed, That's the left zipper flipper switch assembly looking at it board up? That wire looks like it's coming from the coil lug, the common side. That's an odd break but I'll take a pic of mine but I'd guess there should be another loose end to that or that coil will not work.

Just a heads up. Wires are color coded for a reason.

From your pic, and the extra blob of solider on the switch and the same color wire. It should go there.

While you are solidering. Also remove the solenoid expander board and reflow all the solider on it. Its just a good thing to do to make the game reliable.

Ok, took four pics.

Looks like our stuff is different but either way works, thing is my machine works. Study them and decide from there.

IMG_20150625_122134.jpgIMG_20150625_122144.jpgIMG_20150625_122204.jpgIMG_20150625_122118.jpg

Your normally closed EOS switch could use replacing, it look worn right out from the pic.

Did you replace your NC EOS switches? That one was shot on the left side back then.

I did have a strange issue similar, ultimately a possible coincidence but replacing all the molex connector wire ends leading into the power board with new stuff (had to slightly ream out the connector holes) seemed to solve my right flipper not working condition when it magically appeared.

When stuff should work but doesn't I target resistance to flow through those old connectors. For the hell of it unplug those connectors, plug them back in, repeat 10 times each. See if your flipper comes back.