What the 2 drawings show is the external to board wiring, which may allow you to trace the circuit and see if the individual items function, and draw only the correct current. So that may be useful if the problem is a failed outside part. Otherwise you will need the circuit of the PCB to see just what is causing the problem. One option could be to replace the resistor with a much higher value one, 2.2K ohms would limit the current a whole lot, and that would probably enable tracking the source of the high current draw.

 

Ok...I just KNOW that there are some folks out there that find it hard to get through a day without hearing more about this saga of THE MISSING RESISTOR...
I have now brought the machine back to my new place, and hopefully within a few days will start digging back into it, with a renewed vigor.
Stay tuned...

 

The latest: I contacted Steve at Pinball Resource (he’s said to have any and all old Brunswick stuff)...he says there was never a schematic made for this circuit board, but he has several dud boards that match mine. He’s sending one (20 bucks) so that might give a better look and a part or two.
In the next day or two I hope to be able to try the 2.2K resistor MrB suggested and do some tracking...

 

Wow! It’s been a long while away from this project but back into it...
Have the “new” DUD board I got from Steve (remember, it worked better and almost perfectly than the original board) and ordered new, heavier bridge rectifiers. Finally installed them yesterday, gave it a try, and now it’s worse off than before. I get one playfield light on a top alley, flippers work, game start does nothing. That’s it. So power supply is back on the bench and I’m trying to recheck everything with schematic and such. But these negative voltages are really screwing with my brain and what little I’ve gathered over the years. At this point, I’m brain farted on using my meter leads in the right locations—the red lead ok but I’m not sure where to get “ground” to place my black lead. So far, I’m not seeing anything that makes sense to me. I’ve run myself into a hole trying to think about this, and also worry about creating a short...
Can anyone shed some light on this testing for voltages?
(Note: I’ve found that some of the wire colors on the schematic in the area from transformer to BRs don’t match. No problem except the thick yellow wire that comes from the COM point of the transformer I think is supposed to be green according to the schematic.(odd since this wire doesn’t appear it could have been replaced, being manufactured with the transformer) The yellow wire that comes off Circuit Breaker 3 is a smaller gauge, and does continue on into a connector. ...
At this point, I’m hoping to verify the voltages at the BRs but I’m stumped at what I’m seeing...

 

Oops. I rechecked and everything was ok with the new BRs...now, back to trying to see what might be wrong on the supposed “dud” board, and then hoping to finally repair the original board issue...

 

I went back to the schematic and the wire from thr transformer tapped winding is tagged green but then after the breaker it is yellow. And the voltages are written on that drawing so tracing the trans should work well.
There may be a problem with some of the polarized caps being electrically leaky, which can cause lots of grief. I did not revisit the pictures of the circuit board so no comments about that.

 

I believe everything is going “ok” so far, but I’m feeling my way around. At the moment, I have the playfield up and out, laying across the cabinet upside-down. Power hooked up and I’m checking for things that don’t work. Some lamps not working, but could be burnt. I believe voltage to them is ok.(I’m also in the process of trying to ID and label on the underside the lamps, switches and such I think will make it a bit easier to trace on schematic) I know that there are 12 lamps on the playfield—6 are AC that stay on, and 6 are DC that work with the game action.
The POP Bumper does kick the ball but doesn’t score.
I think there are 2 Kickers that aren’t working but do score. (I’ll have to look closer—they may not be kickers, but the 2 just above the flippers do work fine)
And I think there might be a roll-over that don’t work, and a spinning gate (2 are fine) that doesn’t score.
I’m still working with the DUD board as so far it seems to be fine. (I’ll get back to that resistor on the original board a bit later LOL)

 

NowI am wondering about the "dud" board. Is it single sided, or are there traces on both sides? One way that often helps trace a single sided circuit on a board is to have a quite bright light behind it so that the traces an be seen from the component side. Sometimes that works quite well, sometimes not.

 

It’s single-sided too. Funny, but just last night I was holding it up to a bright light to see the traces. It didn’t help me much...I’d like to build a light box to set it on top of and see how that works, in the future. Ended up I was taking a fine Sharpie and drawing some fine lines and crude part outlines to try and make some sense of the area around the original board’s bad resistor. I need to do more study on flow/schematics so that maybe one day I might have just a slight clue of what’s really going on...

 

I’m going to put this post on “hold” for time being, as I’m more focused on working with the “DUD” board now. It seems to only have one issue with it so I’ll detail that in another post.
Thanks for the help so far, and I’m sure I’ll be back to this before too long and try to resolve.

 

My thanks to all who helped. I was able to make the machine work with the “new dud” board as I detailed above—and it played perfectly with the only hiccup being about 3 or 4 targets would score a different amount than originally. Decided to sell to make some room—it sold within an hour of listing to a local that put it in his man cave. He’s happy. Me too.

 

Thanks for the close.

ak