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Centaur drop targets fault

Graham Lowe

Graham Lowe

Registered
Joined
Oct 16, 2013
Messages
135
Location
Skelton, Saltburn, North Yorkshire
Hi all, my Centaur has developed an odd fault whereby when ORBS target O drops it causes the 1,2,3,4 targets also to drop in sequence then reset and drop ahain repeatedly. If the O is not dropped but RBS are then this does not occur. Suspected switch diodes on ORBS switches but replaced and still the same. It is running on a brand new Alltek solenoid driver and MPU. Any suggestions greatly appreciated as it's driving me nuts although likely a simple solution I guess! Cheers, Graham
 
This sounds like a switch matrix fault, with target 'O' bringing up a 'phantom switch', in this case one programmed to spot a 1 to 4 target. These things need three closed switches to create an imaginary rectangle with the phantom switch, where the faulty switch is opposite the phantom

When the problem occurs, take a 'snap shot' of all the switches closed at the time, including the storage trough, in-line targets, and the flipper buttons. I'm wondering about the way it repeatedly occurs as Spot 1-4 - is this while operating the flippers, or without, i.e. does it happen with the ball in play placed in the shooter lane, and no other activity? If not, the flipper button/lane change contacts may be part of the problem

With a copy of the switch matrix, try to plot out the situation where the problem occurs. Target O would only be one corner of the rectangle, but look at the other switches closed at the time. If a rectangle exists with Target O, two other switches and Spots 1-4, investigate the others, especially the one diagonally opposite Spots 1-4

Edit - the chart shows that Spots 1-4 and target O are on the same Row (#8) of the matrix, with Spots on Column 3 and O on Col. 4. If a short exists between the two columns, then O would also register as Spots while the short exists. The remainder of Col.4 are the targets R, B & S, and targets 1 through 4 themselves, though that would need one of them stuck closed as well as having a faulty diode
 
Last edited:
Jay Walker said:
This sounds like a switch matrix fault, with target 'O' bringing up a 'phantom switch', in this case one programmed to spot a 1 to 4 target. These things need three closed switches to create an imaginary rectangle with the phantom switch, where the faulty switch is opposite the phantom

When the problem occurs, take a 'snap shot' of all the switches closed at the time, including the storage trough, in-line targets, and the flipper buttons. I'm wondering about the way it repeatedly occurs as Spot 1-4 - is this while operating the flippers, or without, i.e. does it happen with the ball in play placed in the shooter lane, and no other activity? If not, the flipper button/lane change contacts may be part of the problem

With a copy of the switch matrix, try to plot out the situation where the problem occurs. Target O would only be one corner of the rectangle, but look at the other switches closed at the time. If a rectangle exists with Target O, two other switches and Spots 1-4, investigate the others, especially the one diagonally opposite Spots 1-4

Edit - the chart shows that Spots 1-4 and target O are on the same Row (#8) of the matrix, with Spots on Column 3 and O on Col. 4. If a short exists between the two columns, then O would also register as Spots while the short exists. The remainder of Col.4 are the targets R, B & S, and targets 1 through 4 themselves, though that would need one of them stuck closed as well as having a faulty diode
Click to expand...
Thanks Jay,
I had initially thought it must be a switch matrix problem but got bogged down trying to figure out how! I'll go through it again and report back.....dont specifically remember it happening with flipper actuation but I'll check and look at the other targets down etc as you suggest. Appreciate your comprehensive reply.
 
Graham Lowe said:
Thanks Jay,
I had initially thought it must be a switch matrix problem but got bogged down trying to figure out how! I'll go through it again and report back.....dont specifically remember it happening with flipper actuation but I'll check and look at the other targets down etc as you suggest. Appreciate your comprehensive reply.
Click to expand...
Hi Jay, just had a look at the game following your suggestions, and with game up and a ball in the shooter lane I dropped the O target manially. Nothing happened until I operated the flippers when the 1234 targets started to drop, so your suspicions re the flippers being involved looks very likely. Not sure where to go next as the phantom switch thing ties my head in knots!
 
Graham Lowe said:
Hi Jay, just had a look at the game following your suggestions, and with game up and a ball in the shooter lane I dropped the O target manially. Nothing happened until I operated the flippers when the 1234 targets started to drop, so your suspicions re the flippers being involved looks very likely. Not sure where to go next as the phantom switch thing ties my head in knots!
Click to expand...
And now all playfield lights have gone out and ORBS targets are refusing to reset except at start of the game! Without my doing anything apart from the check mentioned previously......
 
Graham Lowe said:
Ok, sorted that, diode had come off one end of the O switch, resoldered and all of lights also back on. So back to the original issue!
Click to expand...
Fixed Jay. Bad cap on the 'spots 1-4' target. I'd initially thought it might be a cap problem so did a switch test, thinking a bad cap would show up an open switch as closed, but it didn't so threw me off the scent. Anyway, sorted now and thanks again for making me think around the problem again! Put me back on the right track! Cheers, Graham
 
Nice one:thumbs: The Right Flipper is actually in the switch matrix, does it have a stacked switch something like a lane change function?
 
Aston,

Bally couldn't actually use the term Lane Change, which Williams had trade-marked, but that is really what it is. It operates on the three top lanes (with the phrase "Slow, aren't you?" if the ball passes a lit rollover) and the return/outlanes, but the contacts are placed on the cabinet buttons rather than the flipper units. This allows the speech instructions to be used if a button is pressed in the Attract Mode

Funnily, these contacts on the buttons don't register if the playfield isn't connected. I never chased down why, though I suppose the wiring's branched out of the playfield harness
 
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