Sequence Unit Reset Plunger and Wiper Tension - Tech

(Topic ID: 206829)

Sequence Unit Reset Plunger and Wiper Tension - Tech

By okorange

1 year ago

Topic Stats

  • 11 posts
  • 4 Pinsiders participating
  • Latest reply 1 year ago by Terry1
  • No one calls this topic a favorite


Linked Games

No games have been linked to this topic.

    #1 1 year 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 1 year ago

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

    #3 1 year 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 1 year 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 1 year 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 1 year 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 1 year 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 1 year 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 1 year 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!

    #10 1 year ago
    Quoted from okorange:

    Phil, how in the name of hell do you figure this stuff out?

    installing the search ratchet assembly on the search wiper shaft 180 degrees off leads to taking a closer look at what's going on

    same with the metal screen index cam and the shutter panel linkage on the shutter motor shaft. Other stuff like the door plug in upside down, wrong ball lift motor cams for the game and unsynced turning corners are ... umm ... learning opportunities.

    my only defense is I didn't do all the above myself - some maybe.

    besides the mixer, reflex or other undocumented unit diagrams, timing diagrams for the cams is the last major piece of info you need to figure out from the docs how the game works. Even if the diagram is on a schem (like Malibu Beach), it's not very helpful if it's not drawn very well.

    on Malibu, for example, the sequence/winner unit reset switch is 17A (carnival is 15A). The 9 lobes on the cam is probably right, but they should be clustered more ... the gap that represents the time the search wipers are looking at inline wins is around 25% of the total wiper rotation time.

    I don't have a screen game handy, so if you're bored I'd be curious where the cam lobes are. On carnival queen, I'd expect 8 lobes on cam 15 around search wiper positions 49, 27, 23, 19, 15, 11, 7, 3, so the gap with no cam lobes is even bigger - maybe 45%. It's possible there's only 7 lobes and the sequence/winner units aren't reset during the inline win scanning, so no lobe around position 49.

    CQ has no orange section, so one less sequence/winner unit reset is needed.

    btw, at what position are your search wipers locked? The manuals draw the search disc with the wipers at position 50/0, but I recall the wipers were typically locked around position 2 +/- 1/2, and usually in between rivets. I really vaguely recall locking the wipers at position 0/50 had an issue, but don't remember what (is 15A closed or partway up a cam lobe then?)

    the gerlitz video says to lock the search wipers at position 1, but that doesn't work for most screen games. Position 1 is where the 6 number green section is searched, so you don't want the wipers there or search relays will power when the wipers are locked and a ball is in a big green section hole.

    you need the wipers to be locked on/between rivets where nothing is connected and also want switch 15A to be open so the sequence/winner unit reset coils aren't being held powered.

    #11 1 year ago

    As "twit" said, and I found out, locking my Search Disc in pos 1 created
    a few problems.
    With my Search Disc Locked in pos 1, and on a screen game, my Seq Unit would step up for no reason!
    Also, my Search Index Coil would power; without the Search Disc moving,
    my Search Index Coil would power on occasion and BUZZ!!!
    My coil thing was on the tooth, not in the groove, and it would continually try to
    energize causing the BUZZING!!!
    I now have my Search Disc locked at pos 2.
    Sorry for the tangent, but I thought it was very interesting
    Terry K

    Promoted items from the Pinside Marketplace
    $ 10.00
    Playfield - Decals
    Mods for your pinballs
    $ 44.99
    Lighting - Interactive
    Lee's Parts
    From: $ 5,599.00
    Pinball Machine
    Great American Pinball
    From: $ 99.00
    Lighting - Under Cabinet
    Rock Custom Pinball
    $ 169.95
    Cabinet - Sound/Speakers
    Pinball Pro
    $ 18.99
    Matt's Basement Arcade
    $ 65.00
    Cabinet - Armor And Blades
    Texas Pinball
    $ 174.99
    $ 22.00
    Cabinet - Sound/Speakers
    ModFather Pinball Mods
    $ 19.95
    Playfield - Toys/Add-ons
    $ 35.00
    Cabinet - Decals
    Bright Lights Pinball
    From: $ 99.99
    Cabinet - Other
    Lighted Pinball Mods
    $ 6.00
    From: $ 42.00
    Cabinet - Shooter Rods
    ModFather Pinball Mods
    From: $ 159.95
    Cabinet - Sound/Speakers
    Pinball Pro
    From: $ 19.50
    $ 7,199.99
    Pinball Machine
    Little Shop Of Games
    $ 76.00
    Cabinet - Sound/Speakers
    ModFather Pinball Mods
    From: $ 40.00
    Lighting - Interactive
    Professor Pinball
    $ 5,599.00
    Pinball Machine
    Operation Pinball
    From: $ 9.99
    From: $ 42.00
    Cabinet - Shooter Rods
    ModFather Pinball Mods
    From: $ 9.99
    $ 90.00
    Lighting - Under Cabinet
    Rock Custom Pinball

    Hey there! Got a moment?

    Great to see you're enjoying Pinside! Did you know Pinside is able to run thanks to donations from our visitors? Please donate to Pinside, support the site and get anext to your username to show for it! Donate to Pinside