chattering sweep contact

[Alastair]

Had a lane today where the sweep contactor in the chassis would chatter, and the sweep would not move!

Myself (part time) and my full time tech (The Hammer) worked on this problem today. We firstly changed over the sweep contactor with a new one, but to no joy. Decided to change chassis (82-70 s/s omega tek boards), but still the sweep contactor chattered on the other chassis also.
Re-wired C1 plug male pins (on original chassis) and also female sockets , but still no luck. Changed sweep capacitors also, but still the sweep contacor still chattered. So out of despiration changed chassis again, just on the off chance, but still the sweep contator chattered! Change of shift arrived and Head tech started shift.
Next day came into work and discovered Head Tech got lane working. Bit bambuseled as to how he fixed this. What he had done was tried 14 different chassis on the machine and eventually found one where the sweep contactor didnt chatter!! [img]/content/btubb/images/%%GRAEMLIN_URL%%/confused.gif[/img]
We are a 16 lane center by the way!!! [img]/content/btubb/images/%%GRAEMLIN_URL%%/frown.gif[/img]

Good for him as the problem vanished, but I feel that no solution to the problem was found!!

I myself believe that the problem had something to do with the c2-a plug?!? (dont fancy changing the male pins in the chassis at all, would rather re-build a sweep).

Can anybody pin point this problem? Would like to know what to do without changing chassis.

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We are the willing,
Led by the unknowing,
Doing the impossible,
For the ungreatful.
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[felix]

Re: chattering sweep contact

Are You Loosing a Spot Solonoid Relay Chattering?............It's Your B.E. Contol Panel [Master Circuit Breaker]! [img]/content/btubb/images/%%GRAEMLIN_URL%%/wink.gif[/img]

[Louie_IV]

Re: chattering sweep contact

Could also maybe be a bad sweep switch (SA or SB)?? [img]/content/btubb/images/%%GRAEMLIN_URL%%/confused.gif[/img] Or also possibly the brown sweep switch on the control box?? [img]/content/btubb/images/%%GRAEMLIN_URL%%/confused.gif[/img]

Louie

[Rep]

Re: chattering sweep contact

Are your old toggle switches still installed? I know where I am if they're used the contacts will chatter on certain machines. Maybe the switch if installed got moved, or a bad wire in there somewhere? Just another idea

[ewen]

Re: chattering sweep contact

Do you have AMF-Accu score?
I had this same problem in a center I used to do service for . I switched A&MC plugs between the pair of pinspotters. Problem moved to next machine. Found bad LIU board in the scoring.

Mark

[Monkeyboy]

Re: chattering sweep contact

could have been the 24vac relays.
i had that once, backend ran fine but the sweep ant table chattered away (mainly the sweep only on accasion the table)

But it could have been one of a few things ???????

[8270king]

Re: chattering sweep contact

Check the slots in the mother board the boards go into.

If the end is broken the board does not hit the right contacts and sends voltage everywhere.

JK

[Alastair]

Re: chattering sweep contact

Dont believe its a bad sweep switch SA or SB as machine has run fine for days now. If it was a bad connection from the control box it would have shown up by now.
Bit unsure as too what Rep is refering too. Old toogle switches? Are they in the control box?
Yes, do have accu-score system, and yes the lane a board did cross my mind, as have had this before, but with the swopping of chassis, this illiminates this problem. (as an other chassis now works on the lane)
Also did change out relays straight away, forgot to mention this in first post.
Couldnt be the mother board problem either, as im sure we dont have 14 chassis that have this problem!?!
So you pro's are telling me that it couldnt be a c2-a related problem? Believe that that sweep run etc, is controlled by some of the pins in this plug? [img]/content/btubb/images/%%GRAEMLIN_URL%%/confused.gif[/img]
Why did this problem dissapear when the 14th chassis was tried on this lane? Very, very bambuselled! [img]/content/btubb/images/%%GRAEMLIN_URL%%/eek.gif[/img]

[Louie_IV]

Re: chattering sweep contact

Well, your problem is obviously not in the chassis. I think Rep was referring to the toggle switches on the control box. In theory it could be a C2-a plug. The low voltage wires that go to the SA, SB, and control box toggle switches do go through C2-a plug. (Correct me if I'm wrong as I am still learning the 82-70 wiring layout) If there was a bad connection in the plug (probably a bad male pin or wire on a male pin or a bad crimp job), maybe after plugging and unplugging so many times with all those chassis, he finally moved the bad connection or wire to a point where it is temporarily connected. If that's the case, who knows how long it will run until the problem shows up again?

Louie

[Rep]

Re: chattering sweep contact

Mine was a long shot, I meant the managers control toggle switch at the desk, if theyre on our contacts chatter like heck on certain lanes. But if so the lane would probably stay on so I dont think it's that. Could be the sweep switch in the rear control box, or as said earlier a problem with a plug, bad connection or whatever that for now is getting enough signal not to cause a problem. It could very well be something in the C2a plug, I know there's some low voltage stuff that goes thru there and controls some high voltage stuff (cam switches and control box switches I believe, please correct me if I'm wrong). I have a funny feeling the problem is still there and just in hiding, problems just LOVE to hide from the mechanics :p Keep us posted! [img]/content/btubb/images/%%GRAEMLIN_URL%%/smile.gif[/img]

[Andrew]

Re: chattering sweep contact

Is the contactor continuously chattering - i.e. constant rate of on/off/on/off/...? Is there any movement in the motor at all?

If its essentially a buzzing contactor (but the size of the contactor makes more of a chatter), it is likely a low voltage problem. If this is the case, the contacts often don't close at all - hence no motor movement.

You could measure the voltage on the contactor with a multimeter. Compare to the table motor also. You should disconnect the contactor, though before mesuring it - because with the contactor jumping up and down, you're probably not going to get a clean voltage reading (though you might).

If a sweep cam switch was faulty (etc), then you'd probably see the problem less continuously - e.g. a jumpy starting motor, or jerky action, not continuous buzz from the contactor (with no sweep run at all). Anyway, you'll soon know if this is the case by simply using the manual sweep run switch - if the contactor still chatters, it's probably not any input circuit (cams, etc).

I'll assume for the moment that it isn't an input circuit ('cos the process of elimination of obviously changes entirely - i'll leave that to another post if you reply with an update).

Since you tried heaps of chassis on the machine, I suspect the chassis that works fine is different from all the others in some way - not necessarily that the others are faulty, but the working chassis may be masking the real problem.

I agree with Louie in that changing the chassis may have fixed the problem by 'cleaning' the pins (by unplugging/plugging lots). Have you changed back to a chassis that did not work? That'll show you whether this is the case.

A resistive joint (like a slightly loose connection) may be causing a voltage drop in the contactor coil circuit (which involves the omega-tech board, the c2a plug, the m relay, and the sweep on/off switch in the backend control box).

Have you tried the back end control box sweep on/off switch (the two pin one)? You can test it by measuring the voltage across it while the curcuit is on (i.e. the contactor is chattering). If there's any significant voltage drop ( > 1V) across the switch, then it suggests the switch is resistive and should be replaced. The only places in the circuit where a voltage drop should exist are across the contactor and across the transformer.

Given all of that, if there is a low-voltage problem in the sweep contactor circuit, the working chassis may be masking this by simply containing a contactor that happens to be happy with a lower voltage. Not all contactors are exactly the same - the spring tensions may differ, etc - it may even be a different model.

Hope the above novel helps.

Cheers,
Andrew Kennedy.

[Bill LeMieux]

Re: chattering sweep contact

Try a new bin switch and let us know if that helped any.

[Guest]

Re: chattering sweep contact

Rep has the right idea indeed. In the managers control box up front, there is a small diode which controls instructomat. When that diode goes bad, there is your problem. If you do not use instructomat anymore, as most do not, just take out everything except your two manager control wires and it will never happen again.

[pitcherchuck]

Re: chattering sweep contact

It could also be your contacts themselves. We've had this same problem ourselves at our bowling center and we've found out that there are two types of replacement contacts. One set is silver and the other are copper. We've found out that the silver contacts are not as tall as the copper ones so when we put them in the chassis we get the same chatter you've described. We use the copper ones now and haven't had that problem anymore. Just a thought.

[TheLegend]

Re: chattering sweep contact

Originally posted by pitcherchuck:
It could also be your contacts themselves. We've had this same problem ourselves at our bowling center and we've found out that there are two types of replacement contacts. One set is silver and the other are copper. We've found out that the silver contacts are not as tall as the copper ones so when we put them in the chassis we get the same chatter you've described. We use the copper ones now and haven't had that problem anymore. Just a thought.

<font size="2" face="Verdana, Helvetica, sans-serif">Used to run into this problem with brand new contacts. I ended up checking every new one I installed by holding the contactor closed and seeing how much the floating point springs depressed. If they barely moved (or ot at all) I would then carefully push the top points down.