Sorry for prolonging this thread but t2 hates me. Still have string #3 down.

J120 has 1-brown 2-orange 7-wht/brn and 8-wht/orange

J121 as described by John pins 3,5,6,9,10,11

I buzzed all pins on J115,120,121 and they go to their fuses or Transistors Q's
There does not seem to be any pins accidentally soldered together etc. I have repinned and put new connectors on all plugs.

I accidentally miss connected J121 one pin to the left so pin 2 was in connector 3. The lhs globes came on strobing like inserts. So I'm guessing the connector is fine. Put it back properly and the lhs is still dead.

I got 8.2vac on pins 8-11 and 0vac on the rest

I also still have flasher rhs flipper flasher dead as well although it's back glass cousin does flash

I hope this can trigger someone's thoughts as to a possible solution. I'm good at removing driver pcb's now