Sequence Unit Reset Plunger and Wiper Tension - Tech

By okorange

1 week ago


  • 9 posts
  • 4 Pinsiders participating
  • Latest reply 3 days ago by okorange
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    #1 8 days ago

    The replay circuits weren't working on my Carnival Queen and I was having a hell of a time figuring out what was going on. First of all, nothing was working. That turned out to be the normal index adjustment, which solved some of it. In-line scores pulled in the search index but the red and green replay counters weren't stepping, although the meter was adding credits - without stopping! (Man, this was probably an operator's worst nightmare). That issue was caused by a funky wiper which is (pretty much) fixed, although I'm not so sure it won't happen again. Sections still weren't scoring. Usually that's the change-over switches, so I adjusted them and it didn't matter. Anyway, after a bunch of frustration I found the problem to be the sequence unit reset plunger. I have attempted a few times to clean and adjust the switch but it's pretty delicate. So I decided to just close it permanently to see what would happen. The sections now score perfectly as well. So the first question is, what is the purpose behind this switch at all, and can I just leave it closed? Second question - I am worried the "I" wiper (outside row) won't continue to work for all colors because someone mangled it pretty good in the past and I had to fool around with the bend and also sort of make some sideways adjustment as well to get it to work in all colors. Any ideas to make this reliable going forward? TIA.

    #2 7 days ago

    If you don't mind me asking, what are the "change-over switches"??
    Terry K

    #3 7 days ago
    Quoted from Terry1:

    "change-over switches"

    Terry, they basically set the mode from 'plain bingo' to sectional scoring. They are present on every Magic Screen game and direct the scoring circuits appropriately.

    @okorange, I seem to recall this coming up in the not-so-recent past somewhere. Maybe when I was fixing up my Bounty several years ago.

    I'll see if I can dig that up. I think Phil H. answered that question for me, but I think looking at the schematic will make that pretty clear to me now. We'll see!

    #4 7 days ago

    While the sequence unit is physically in the act of resetting, it cuts off power to the search index if the game is not in the act of paying out.

    I haven't found the correspondence I was talking about, but from the looks of the schematic, because the sequence unit is only really engaged in sectional scoring, I'd guess it is to handle the difference in physical time between scoring sections vs. straight bingo if you have only a couple of sections exposed (Pos A-D). In other words, the control unit keeps on turnin' if there's no sectional payout. But, then again, normal bingo winners are weighted towards the front of the search disc (in rotation).

    That said, it's just a guess. Looking at the schematic, as long as your unit is operating properly, it looks like that could be an optional switch.

    Perhaps Bally wanted to make sure that a gummy stepper wouldn't cause undue payout problems?

    It would have to be pretty screwed up, though. Bally put a goodly number of blank rivet positions on the search disc to account for this, it appears.

    #5 7 days ago

    Found them. 15A & 15B cams on CU.
    I like the talk about the seq unit and contacts(switches)!!!
    On occasion when I move my Magic Screen I will get my Search Index Coil buzzing.
    It seems to be when my Seq Unit is stepping.
    I hope I'm not hijacking this thread; just wondering
    Terry K

    #6 5 days ago

    @bingopodcast I think your assessment is correct. Thanks for that. I'm going to go back in and try to get the adjustment correct, I feel like maybe I'm taking the lazy man's way out!

    #7 5 days ago
    Quoted from okorange:

    I feel like maybe I'm taking the lazy man's way out!

    I know, just like me, that that will eventually drive you nuts if you don't fix it.

    #8 3 days ago

    here's the conclusion from the back-n-forth with bpc:


    The sequence unit reset plunger switch is drawn inconsistently on the screen game schematics. Sometimes NO, sometimes NC.

    It's a problem with what "normally" means when talking about switches. Usually "normally" is right after the reset cycle reset or at the end of the standard game. In this case, "normally" is right after the unit is reset.

    Unlike most of the stepper units that reset and step once during the reset cycle, the sequence unit resets and sits there until it starts stepping all the way up. If you look at how the plungers, link arms, pawls and the ratchet interact, you'll notice the reset coil plunger sucks in when the coil is powered and the pawls are latched up off the ratchet. Even when the reset coil power is removed, the plunger does not come out of the reset coil until the step-up coil powers and unlatches the arms to drop the pawls back on the ratchet teeth.

    So given the physical reality of the unit, the switch really is normally open. It opens when the reset coil powers, and doesn't close until the unit step-up coil pulls in it's plunger. Note also that the wipers don't turn until the step-up coil turns off...then the springs will pull the linkage arms back to the rest position and the pawl pushes the wipers around at the same time.

    Because there's a bypass switch around this part of the circuit that is closed when the sequence unit is reset, it really doesn't matter if the plunger switch is open or closed once the wipers reach the reset position. The plunger switch must be closed while the wipers are stepping up, and open while the wipers are free-spinning back to reset.

    In effect, the plunger switch is undocumented type NW - Normally Whatever (TM).


    that doesn't really address the purpose of the switch. As bpc said, the goal is to prevent the search index coil from powering while the sequence and winner units are resetting. If another win is detected with those units partially reset, you'll likely add too many steps to the winner unit and get an overpay.

    if you look at a search position chart for a screen game, the sections are separated by three non-connected rivet positions (e.g. Blue is pos 25, green is 21, red is 17, ...). At the center position of each of those gaps (e.g. 23, 19), the cam switch that resets the sequence and winner units closes, so that's how the sequence/winner units reset between looking at each section.

    so you have a race condition - will the sequence/winner units be reset before the wipers hit the next position for win detection? If not, the circuit is disconnected and you won't get the potential overpay because the win will be ignored.

    In addition, if the sequence unit doesn't reset all the way due to cruddy wipers, the close-at-zero switch will never close and sections will never pay. Another safety that prevents possible overpay.

    why there's a sequence unit open at top switch in parallel to rivets/wipers that do the same function? ... who knows. On the original carnival queen schem for games 1-3000, the sequence unit rivets/wipers box is labelled with different lettering, implying it was added to the schematic later. It is completely redundant.

    that just leaves the question of what happens if you permanently close the plunger switch. If your sequence unit wipers whizz back to reset, you'll almost certainly not have a problem or notice any difference...but can you sleep at night with a known misadjusted switch?

    #9 3 days ago

    "but can you sleep at night with a known misadjusted switch?" No, and I'm sure you couldn't either, that is our mutual sickness.

    "At the center position of each of those gaps (e.g. 23, 19), the cam switch that resets the sequence and winner units closes, so that's how the sequence/winner units reset between looking at each section." Phil, how in the name of hell do you figure this stuff out?

    OK guys, I will fix the frickin' switch!

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