Two-player EM game. Plays fine in both 1 and 2 player games, except both lites that indicate which player's turn it is stay on all the time. They do not alternate as they should. I completely cleaned, serviced and adjusted all contact points as I thought they should be, but no change. Before I cleaned it, the lites would randomly come on and off. I checked the schematic thinking this was an easy fix, but I can't figure out what's wrong. Any ideas?

Forgot to add: the cleaning and adjustment was on the "ball count unit".

Thanks Curriedog. I do remember checking the operation of that specific latch/trip mechanism before, but I just tested it again for electrical integrity of coils, contacts and switch leaves - everything checks out. Any other thoughts?

I see it now -- you're looking at a different set of lites. The ones you mention are at the bottom of the backglass that indicate how many players there are. ("1 or 2 can play"). Those work OK. The offending pair I described are above each set of score reels that indicate which player is "up" ("1 Up", "2 Up"). I think they're misnamed on the schematic as "1st" and"2nd" (Look 4" to the right.) The wire colors agree. So I am confused by that section of the schematic as to where the problem really is.

I checked and cleaned that N/O switch twice. I manually operated the BCU and it works fine. Checked all the wires and connections. No visible flaws. All contacts are spotless and line up perfectly. Again, the only issue is that both lites remain on at the same time for the entire 2-player game and do not alternate as they should. I guess I'll have to disassemble the BCU stepper -- a last resort. I don't know what else to do. Thanks for your moral support!

Hello Rolf: Thanks for your response. I ruled out hacks as I've had the pin for 6 years and it was working great until it started doing this "both-lites" thing just recently. I will try all of your ideas and let you know what I find!

Thanks for the feedback Mopar. I agree about the nasty wire strands -- they can be nearly invisible. I will again disassemble the BCU and this time examine it much more closely.

Meanwhile, Rolf - I had a chance to check out all of your recommendation. Everything is fine, except that one wire color "white-gray" you highlighted does not go to a solder lug on the BCU disc but rather is a grounding lug only for the BCU metal frame. That's odd as I didn't see it represented that way on the schematic. I confirmed its continuity with the "game over" relay M/B switch blades and with ground on the inside cab lower board. FYI, the BCU two-step movement DOES NOT turn off lites momentarily. I checked this both manually and with play. I will check your newest Jones plug ideas tomorrow. I have had failure problems with Bally Jones Plugs before. Sleep well. Thanks!

Hello Rolf: The answer to your latest question - the 2nd coin relay (latch/trip) is located in the back box. I am going to do the unsolder pin tests you recommend now, unless you have new ideas. I haven't done that yet because I have been taking the BCU apart again and also checking every single pin connection on all of the jones plugs. Thanks!

Oh, and yes, you are correct: it is wire-color-gray-white, not white-gray as I described!!! By the way, I have found nothing wrong anywhere so far in either the disassembled BCU or the jones plugs. I even took the spider finger blades apart and cleaned checked them! I do not advise anyone to try this without coding each blade and taking reference photos first!!

Hello again Rolf - test results are in, and they're not good.

I took apart the 2nd coin relay and examined/cleaned all components. Then tested connections. everything checks out - all good.

Next, I unsoldered the blue-orange wire from the 2nd coin relay as you suggested and ran a test play. The 2nd Up lite did not come on, but each players scored correctly and alternately. The "1st Up player" lite stayed lit throughout the games.

Next, based on your red line theory, I thought it would be a good idea to unsolder BOTH ends of the blue-orange wire at the same time - one from the 2nd coin switch, and the other end from the "2nd Up" lite. I then ran a jumper wire between these two points and ran test plays. If there was a fault in that line, this would reveal it. Nothing changed. Both lites stay on continuously. GRRRRRR!! Could there be something amiss with the "2nd player" relay (which I also inspected and tested)?

I should re-mention that the one-player game plays as normal (with no 2nd Up lite on).

Can I send you photos of anything? Thanks for your insights! I'm trying not to lose hope!!!

As your suggested, I disconnected the y-r (yellow-red) wire from the BCU and tested. Only change was the "2nd Up" lite did not come on at all for either player's turn. "1st Up" lite remained on for both players' turns. Scoring was correct for each player. Thanks for trying. I'm open to any suggestions!

Rolf: Yes, you are correct. When blue-orange wire is connected to its respective 2nd coin relay lug as per the schematic, one-player game plays normally and the "1stUp" lite comes on and stays on as it should when the credit button is pushed once, at start-up, asking for a one-player game. Ball is ejected and game is ready to play. But when the credit button is pushed a second time asking for a second player, the "2ndUp" lite comes on also (this should not happen). Both lites stay on thru game end. They do not alternate to indicate which player is "UP".

The other pair of lites that indicate how many players have paid, perform as they should ("1 or 2 can play").

Here's more info that may be unimportant:

When each "Player Up" lite comes on, so do the strip lites that illuminate each player's score reels.

I have the game wired for free play, and both coin mechanisms work for coin drops, but are not used. I did check these out thoroughly for faults, etc.

The machine worked fine for 6 years until the two "player-up lites" began to flicker intermittently back and forth during a 2-player game.

"Fixin"

Mopar: Your observation makes sense and is easy enough to tackle. I've already taken the BCU apart twice, so a third time is no big deal. And you're correct, I already know by lifting, as Rolf advised, which blade controls the up lites. I was relying on visual inspection, so the razor blade technique drew a "wow" from me. I did inspect all the spider leg buttons: they are worn flat a bit as expected for a 46,000-game machine, but they do line up perfectly with the BCU disc's flat rivets. I filed them accordingly to eliminate crossover and give them a more rounded mating point just to be sure.

Rolf: I will try Mopar's idea first. I have a pacemaker, so tampering with live voltages is scary and risky business!! hahaha.

pinballdaveh - your simple test was more revealing than I thought!

Thanks to all! Will advise...

I had been scraping all the bakelite real estate between pads off the disassembled BCU disc before I saw your latest post. I also took the opportunity while it was apart to carefully separate every wire jump on the back side using a dental pick. They were crammed on top of each other tighter than... well, they were mashed together pretty good. (I didn't trust the insulation after 40+ years.) I put it all back together. Here's where I owe you an apology: I didn't think anything would be different. Then I fired it up. Hit credit for one player, then hit it again. The 2ndUp lite did not go on. Eureka! I don't know if it was the scraping or the separating of wires, but it worked. I let out a huge cheeeez! Played several games to verify. Thanks to you and all the great minds who solved this one and also confirmed my first suspect: the BCU.