great, "2,3,4 thousands" light up. I have not yet seen the inside of a Royal Flush. Here an idea - want to try ?
Look at oldpins JPG (post-3). Side by side are the wires soldered-on (at a bakelite plate on the unit). So "A-0-Mar-1000-Light", "B-1-Mar-Wh-2000-Light", "C-2-Mar-mingled-with-White-3000-Light", "D-3-Mar-Or-4000-Light", "E-4-Mar-mingled-with-Yellow-5000-Light".
My idea (can't remember having done once): With a short Jumper-Wire make a permanent connection*** "B-1-Mar-Wh-2000-Light" to "E-4-Mar-mingled-with-Yellow-5000-Light" (((You just jumper "feeding the lights"))). Questions:
When "B" lights-up --- does "E" light up ?
When "E" should light-up --- DOES "B" lights-up ?
(((May want to try on WORKING stuff - jumpering "B" and "D" --- to prove my theory right-or-wrong (?) )))
With this jumpering we test "is the fault in the stepper unit OR is the fault in the wiring to the lights ?". I do not know - please tell me: "Where is the stepper unit mounted" ? IF (if) it is NOT on the playfield: A Jones-Plug can be faulty.
connection***: Clip-on the gator-clip "one side of the Jumper-Wire" at Solder-Lug "B", clip-on the other end / gator-clip at Solder-Lug "E". When You do not have a Jumper-Wire having gator-clips: Simply wrap the bare end of a wire around the Solder-Lug. Greetings Rolf