Mr & Mrs Pacman Issues...Still

dieseldogpi

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Been working at this for a while. After having board work done, and then double checked, the issue is still occurring. Here's my main (but not my only) issue at this point:
Games starts fine, start button starts the game, flippers work fine, no stuck scoring switches, BUT the other solenoids do not fire as they should. This occurs within the game and in test mode. The coils that work are the ball kick out, the other kick out holes, and (maybe) the individual coils for the drop targets (there are coils in this game that individually drop the drop targets). The other ones don't fire. If I hit the switch for the pop bumper, one of the coils to drop the drop targets fires...and repeated hits makes this same wrong coil fire every time. Other switches operate other of these drop target coils. I have an almost fully populated second play field that I can swap some stuff, just not sure what could cause this. Not the boards, and not the wiring between the boards. Maybe a couple of shorts? Please any direction would be appreciated. Thanks.
 
Have you checked the wiring under the playfield?
I have and there is nothing MAJOR, I am going to go through more thoroughly, but its not like i see any major spots where there could be shorting.

Check the diodes on the coils...one may be shorted. Also check the coin door/wiring ... it maybe shorting on something.
I didn't think a shorted diode could cause this. As far as the coin door wiring, what exactly would I be looking for?
Thanks again.
 
Sounds similar to a problem I had with mine. There's a relay that toggles the output lines between one set of outputs and the other. I don't remember what the issue was with mine. Either the relay itself was bad or part of the relay's circuit. Check the schematics for details on how that works and hopefully that'll get you up and running.
 
Sounds similar to a problem I had with mine. There's a relay that toggles the output lines between one set of outputs and the other. I don't remember what the issue was with mine. Either the relay itself was bad or part of the relay's circuit. Check the schematics for details on how that works and hopefully that'll get you up and running.

This sounds promising! Which relay? There is a relay on the tiny expander board under the playfield...this one?
 
This sounds promising! Which relay? There is a relay on the tiny expander board under the playfield...this one?

Yeah, that's probably your issue. If you look at the playfield wiring schematic You'll see that the coils you're talking about are all powered through the relay on the solenoid expander. If this relay gets stuck on or never energizes one set of those coils won't work and the other set will be energized instead. Looking at the schematic, in your case it looks like the relay is never energizing rather than being stuck on.

In one position the relay powers one set of coils and in the other position it powers another set. The solenoid expander itself is driven by a lamp driver SCR output. So... believe it or not a lamp driver problem could actually cause this.

The lamp driver SCR output drives an optocoupler on the solenoid expander board which in turn energizes the relay. Should be simple enough to trace through it. There's also a lamp in parallel with the optocoupler. Also make sure that lamp is good but that wouldn't be my first guess.

Good one, TheShanMan.

EDIT: Okay... to satisfy my own curiosity I figured out which lamp driver circuit drives the solenoid expander. Should be pin 12 of connector J2 on the aux lamp driver. The schematic shows it as "to aux driver J1-3" I suspect this is an error because the solenoid expander schematic shows the input as J1 pin 2. I would put the game into test and make sure the lamp connected in parallel with the optocoupler on the solenoid expander is flashing. If the lamp is good and it's not flashing you know the SCR (Q14) on the aux lamp driver is open. If it is flashing I would make sure you've got switched illumination voltage (around 6VDC) on pin 1 of the optocoupler on the solenoid expander and strobing ground on pin 2 (with the game in lamp test). If you've got that then check for strobing ground at pin 6 of the optocoupler. If that's not there the optocoupler is bad. If it is, it's time to look at the relay.

The first thing you might want to check is for bad solder joints at the aux lamp driver and solenoid expander boards. The procedure above will troubleshoot it assuming all connectors are good.

I think that should be right :p
 
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Yeah, that's probably your issue. If you look at the playfield wiring schematic You'll see that the coils you're talking about are all powered through the relay on the solenoid expander. If this relay gets stuck on or never energizes one set of those coils won't work and the other set will be energized instead. Looking at the schematic, in your case it looks like the relay is never energizing rather than being stuck on.

In one position the relay powers one set of coils and in the other position it powers another set. The solenoid expander itself is driven by a lamp driver SCR output. So... believe it or not a lamp driver problem could actually cause this.

The lamp driver SCR output drives an optocoupler on the solenoid expander board which in turn energizes the relay. Should be simple enough to trace through it. There's also a lamp in parallel with the optocoupler. Also make sure that lamp is good but that wouldn't be my first guess.

Good one, TheShanMan.

I definitely like where this is going. I have checked that actual lamp in the past and it is lit, now you will have to excuse me because I'm not so versed in all this, what exactly am I looking for on the expander board? Would I be better off replacing with a new one for long term durability, or is this something that rarely breaks?
 
I definitely like where this is going. I have checked that actual lamp in the past and it is lit, now you will have to excuse me because I'm not so versed in all this, what exactly am I looking for on the expander board? Would I be better off replacing with a new one for long term durability, or is this something that rarely breaks?

I added some detail above. I don't think there is a "new" option for this board but it's dead simple to repair and shouldn't fail often.

EDIT: Also, that lamp should flash in lamp test. If it's on solid, that's a problem.
 
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Awesome. there is a new option for the expander board itself, but if it is on the aux lamp, then that wouldn't even help, unless its the relay. I will try to look at it tonight and report back with my findings. Thanks again Lindsey and TheShanMan for the idea.

EDIT: Thinking about it now though, I don't think that bulb (the one wired to the expander board) it has always been on solid.
 
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The expander board has two main components - the relay (which does not fail often) and the MOC3011 optoisolator (which I have seen fail). If you want to replace the MOC3011, I can send you one, or you can send me the board and I can test it, no charge, and repair it as required. really want to get you through this.

Chris
 
The bulb tied to the expander board does not fully blink in test mode. It does get some what dim then bright, then some what dim then bright, etc. Is this what it is supposed to do?
 
Sounds like what mine did IIRC, along with a semi-quiet buzzing noise. Relays make a distinct clicking sound though so if you don't hear it clicking on and clicking off, I think you've found your problem.
 
Sounds like what mine did IIRC, along with a semi-quiet buzzing noise. Relays make a distinct clicking sound though so if you don't hear it clicking on and clicking off, I think you've found your problem.

Hey theshanman, when you put yours in test mode, does the bulb off The expander board blink on and off, or pulse but remain on?
 
Tested the expander board. Had 2.6 v at pin 1 on the optocoupler, something like 1.4 at pin 2 and 2.6 at pin 6. Fluctuated by .2 v with the pulsing. I did not here the relay click unless I shorted pin 1 and 2 of the optocoupler. So this is the optocoupler thats bad then?
 
Tested the expander board. Had 2.6 v at pin 1 on the optocoupler, something like 1.4 at pin 2 and 2.6 at pin 6. Fluctuated by .2 v with the pulsing. I did not here the relay click unless I shorted pin 1 and 2 of the optocoupler. So this is the optocoupler thats bad then?

Shorting pins 1 and 2 of the MOC3011 will short around the input LED effectively disabling it so the relay is probably on all the time due to a shorted SCR on the aux lamp driver and shorting those pins turned it off. That's why it clicked.

That's my diagnosis anyway.

I have a lamp in a socket with some wires attached that I use in a situation like this. If you want to test the SCR on the aux lamp driver once and for all, remove the connector on the aux lamp driver and check the SCR in lamp test with an external lamp. That will tell you once and for all if the SCR is bad. The lamp should flash just like all the others.

This should be the case with the lamp connected in parallel with the optocoupler anyway but that will tell you for sure, under the correct load (approx).

EDIT: If you want to be ghetto you could fix it by using an unused SCR from the main lamp driver board. If you have the SCRs on hand obviously use a new one but I would consider doing that if I didn't have any.
 
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So you don't think it is the opto, it is an SCR on the aux board? And your saying to test, take a socket and lamp, and hold the wires to pins on the aux board that would go to the opto board?
 
So you don't think it is the opto

Not based on what you've said so far, no.

it is an SCR on the aux board?

That's what it looks like at this point. Like I said earlier, the SCR that drives the optocoupler on the solenoid expander board is on the aux lamp driver.

And your saying to test, take a socket and lamp, and hold the wires to pins on the aux board that would go to the opto board?

I'm suggesting first that you make a tool you can use in the future. A lamp socket with some wires attached that you can use as a "test light". Then connect one end to ground and the other to the pin on the aux lamp driver that goes out to the solenoid expander board (J2, pin 12 on the aux lamp driver) with the connector disconnected.

At this point, given that the lamp connected in parallel with the optocoupler is on solid, we can assume that the SCR driving it is shorted and just replace it. The test above was just to be absolutely sure. Probably not totally necessary in this case, but a good exercise anyway.
 
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Tested with the bulb and wire rig, connected one side to pin 12 of J2 and the other to a ground, put it into test mode, and the bulb didn't blink or light up at all.
 
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