Charleston - Yeah, I'm plenty comfortable soldering so I'll plan to replace the resistors, not the boards - thanks for the link, I searched but didn't find those!
Did you go LED on the topper bulbs as well?
Quoted from Chosen_S:
Look for a common ground black wire that is connected to the little boards, unsolder it , it there's more than 1 black wire connected to the same spot disconnect both, but they've them soldered together, wrap them up. Put in an LED flasher and test it...
There are ground connections on both sides of the boards, save one. I've been staring at the wiring itself to assess where the loop begins and ends but it's making me go a little crosseyed.
One of the boards - the first in the line, as far as I can see - controls the 1251s, so I won't be touching that one. There are 3 more flasher boards under the playfield; of these, 2 have pairs of ground wires on either side of the board, but what I take to be the last has, naturally, only one. My question is, if I simply disconnect the grounds on the second board (since the 1st is controls the 1251s), am I done/does that not effectively disconnect the grounds from the whole line? I'm fine with disconnecting all of them of course, if that's what it takes. Just trying to understand/avoid extra work.