Two steps forward, one step back...

DillonFoulds

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Well, tonight I set out to straighten out all the feature lamps on my Mata Hari...

Replaced the playfield fuse. Lifted off a couple mylar slingshot protectors that were peeling off and getting bothersome, replaced the last (12 or so) 44's with 47's, replaced a couple sockets that had bulbs that wouldn't turn on, finally had all the bulbs lit up except one! (2x Potential)

Checked socket, yup, continuity on both +v and ground, jumper-ed light from a different socket, bulb lights up, that's a good sign. Check continuity from socket to Lamp board J3 connector, all good there, check continuity from J3 to Q46... all good.

Assumed it was a bad SCR, time to check schematics in hope of a free SCR I can swap to test out (don't have any new ones on hand...). Nothing on the schematics looks to be available, all SCR's (2n5060's) are used up... maybe I'll just swap a couple SCRs until my electronics shop can order in new parts for me... Q4 sounds like a nice candidate... Oh look Q4 is on Pin 28, turns out it isn't even in use after all. Swap SCR's, and voila, working light!

Finish going over my lamp sockets, removing wire, scrape socket tips, resolder wire to the tip of each socket. Fire it up aaaaand....

End-of-ball bonus (100) is now flashing reverse from the rest of the bulbs in lamp test...

AARGGGGGGGGGGGGGGGGHHHHHHHHHHH!!!

Sleep time, I'll have to think about this again tomorrow. Anyone else feel like making everything concrete sometimes just causes other problems?
 
Will pulling the SCR (Q4) on my board have any adverse effects, though? I don't see how it would have changed anything, but maybe there's something I simply overlooked?

Maybe I'm going to have to replace the 1k Bonus SCR (Q14) while I'm at it, too...
 
Will pulling the SCR (Q4) on my board have any adverse effects, though? I don't see how it would have changed anything, but maybe there's something I simply overlooked?

Maybe I'm going to have to replace the 1k Bonus SCR (Q14) while I'm at it, too...

My initial thought was that one of the SCRs you swapped is installed incorrectly. I would consider pulling both of them and see if the new problem goes away. If it doesn't I would suspect Q14 next.
 
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