Commerce City, CO
I had a very similar issue (not quite as weak as yours). No other coils on the node board had exhibited any weak behavior either.
I tried all kinds of stuff with the mech (lube, replaced bushings, polished all the friction surfaces, slight bending of the 'fork', felt spacers to take the slop out), replaced the coil, flashing software (quick and full), and tried swapping node boards 9 and 10. None of that resolved it for me.
Ensure that the connections are SOLID in the power harness connector (at both the PS and the playfield harness). I ended up playing with the pins in the playfield harness (stretched the pins out a bit as they seemed a bit compressed) and that seemed to do the trick for me. You can even play around with a jumper wire if you want to bypass the harness connector entirely.
