TECH: 6 in 1 switcher is kicking my PS into Protection mode

Fatality83

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TECH: 6 in 1 switcher is kicking my PS into Protection mode

I have had my Jamma 6 in 1 switcher for a little over a year now. Months ago, sometimes when I would turn the game on, I would only get a/c voltage. Most of the times unplugging the game or jamma harness or waiting a few minutes would get it to work again. I eventually replaced the power supply, thinking that was the culprit. All was well for a day or so and eventually it did it one or two more times and then continued working for some time after that.

I just moved and I unplugged all the games from the switcher before I moved the game so it was safe to move. I go to reinstall everything yesterday and once I get to the third or fourth slot, the PS starts going into protection mode. Basically, the game comes on for a second, than the PS LED shuts off and stays off. I have to turn the game back off for a second or two until the led on the PS and switcher flashes. Than I can turn it back on and sometimes it comes on and sometimes it doesn't. I originally thought the issue lied with slot #3 as every time I would have a game in that slot, it would go into protection mode. Now I am not sure though as it seems to be doing it randomly even with pcbs out of slot 3.

I pulled the switcher out yesterday and reflowed solder on pretty much every connection on the solder side of the board. I reinstalled it and added a game to a slot and powered it up to test it one by one. I got all the way through every slot and it was still working. Success I thought happily. Well it turns out, this beast was just waiting for me to move the switcher into place and screw it down. Than it started giving me issues again. Does anyone know what I can do to trouble shoot this thing? I could probably figure out how to check voltage on it and everything but it seems like something is shorting out causing the PS to go into protection mode. I have no idea how to check for that. I see no obvious problems such as touching connections or anything. Please help. I would rather fix this one than have to waste money on another. I do have a logic probe and multimeter I just am not sure how to use them in this application
 
I would say cold solder joint (I know you re-flowed it all) being caused by "flexing" of the board when you screw it down. I am 99.9% sure that if you use the legs that came with it, or use standoffs of some kind, your problem will go away.

Are the wires on the solder side for the mods being pierced at all? That could be the issue too. If you aren't using standoffs, when you screw the switcher to the cab, one or more of the mods wires could be getting pierced by the legs of the components. Make sense?
 
I would say cold solder joint (I know you re-flowed it all) being caused by "flexing" of the board when you screw it down. I am 99.9% sure that if you use the legs that came with it, or use standoffs of some kind, your problem will go away.

Are the wires on the solder side for the mods being pierced at all? That could be the issue too. If you aren't using standoffs, when you screw the switcher to the cab, one or more of the mods wires could be getting pierced by the legs of the components. Make sense?

Thats what I thought, the board flexs with the weight of the pcbs in some of the slots and breaks a connection somewhere. I reflowed bacially all solder on the back except the little tiny dots of solder on the back. I am using the little feet that came with the board to mount it. I basically have a shelf installed about the middle of the cabinet and have the board attached to the feet which get screwed down to the shelf. When I redid everything and screwed it down (and it stopped working) I didn't even screw it down that tight. I actually think, just moving the board from where it was over to the right a few inches is what caused it to stop working again. All that is on the top of the board is a bunch of yellow resistors. Not sure if that would cause it or not.

Also, everything looked ok with the -5 volt wires and such. They are not touching anything that I am aware of. I am thinking about completely removing them though to see if that changes anything.
 
This has happened to me on my test bench before without anything even installed in the switcher. It was one of the mod wires being pierced from when I taped them to the back of the switcher. I figured it was something like that.
 
When I remove most of the pcbs it works just fine. It seems like it either has to do with the weight of the pcbs flexing the board in some spot or that pcb being in the slot affects it somehow.
 
I can now officially earn the bonehead of the month award. Got home today and messed around with it some more. It was still acting up. I pulled it out and reflowed solder on even the tiniest of connections. Checked to make sure the -5 volt lines were not shorting out anywhere. Reinstalled it back in the game. It still was acting up. I noticed that when there was only one game in the switcher it would work but if I added two or three games it would go into protection mode. I was gonna give up for the day and just order another switcher. Luckily I didn't. I got my multi meter out and checked voltage directly at the power supply. 12 volts was around 12.1 and 5 volts was around 5.1. -5 volts was a little low at 4.6. I than unplugged the Jamma harness and tested voltage at the end. the 12 volt line was reading only 10 volts! I increased the voltage an voila it magically started working. So that old saying "always start at power is very important. Wished I would have listened to it. Either way I am glad its now working and that I didn't waste my money on another switcher. And on the bright side, I don't think my switcher will be having and cold solder joints anytime soon! Even though this switcher does not actively power any pcbs on start up, apparently having a game in does have an impact on the voltage somehow.
 
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I can now officially earn the bonehead of the month award. Got home today and messed around with it some more. It was still acting up. I pulled it out and reflowed solder on even the tiniest of connections. Checked to make sure the -5 volt lines were not shorting out anywhere. Reinstalled it back in the game. It still was acting up. I noticed that when there was only one game in the switcher it would work but if I added two or three games it would go into protection mode. I was gonna give up for the day and just order another switcher. Luckily I didn't. I got my multi meter out and checked voltage directly at the power supply. 12 volts was around 12.1 and 5 volts was around 5.1. -5 volts was a little low at 4.6. I than unplugged the Jamma harness and tested voltage at the end. the 12 volt line was reading only 10 volts! I increased the voltage an voila it magically started working. So that old saying "always start at power is very important. Wished I would have listened to it. Either way I am glad its now working and that I didn't waste my money on another switcher. And on the bright side, I don't think my switcher will be having and cold solder joints anytime soon! Even though this switcher does not actively power any pcbs on start up, apparently having a game in does have an impact on the voltage somehow.

Awesome. Glad you fixed it...bonehead.
 
I can now officially earn the bonehead of the month award. Got home today and messed around with it some more. It was still acting up. I pulled it out and reflowed solder on even the tiniest of connections. Checked to make sure the -5 volt lines were not shorting out anywhere. Reinstalled it back in the game. It still was acting up. I noticed that when there was only one game in the switcher it would work but if I added two or three games it would go into protection mode. I was gonna give up for the day and just order another switcher. Luckily I didn't. I got my multi meter out and checked voltage directly at the power supply. 12 volts was around 12.1 and 5 volts was around 5.1. -5 volts was a little low at 4.6. I than unplugged the Jamma harness and tested voltage at the end. the 12 volt line was reading only 10 volts! I increased the voltage an voila it magically started working. So that old saying "always start at power is very important. Wished I would have listened to it. Either way I am glad its now working and that I didn't waste my money on another switcher. And on the bright side, I don't think my switcher will be having and cold solder joints anytime soon! Even though this switcher does not actively power any pcbs on start up, apparently having a game in does have an impact on the voltage somehow.

first off, with a switching mode power supply, the other voltages besides +5 will show way off when no load is present. that's why I hook a coin door lamp up to power supplies if I'm testing them without a game hooked up. you can risk damaging the internals of the power supply running with no load.

second, I want you to consider how much power you lose between the power supply and boards that plug into that switcher. the power has to travel from the power supply, through the JAMMA wiring, to the pins in the JAMMA harness, to the edge connector at the switcher, then bounce around through some relays, and through more JAMMA "harnesses" (the slots on the 6-in-1 the games plug into) and then through your game boards. I don't know exactly why it was tripping the overcurrent protection, I mean, maybe that's what it's supposed to do, but the "solution" that you realized was that you weren't feeding it enough power when you consider all the stops along the way that voltage has to travel through.

I also strongly discourage using a cheap power supply with one of those 6-in-1 switchers. if it's an older unit, another reason the overcurrent protection can trigger is if the +5 adjustment is dirty. turning the knob back and forth a few times can clean it using the wiper inside, but you won't know what the +5 will be set at. so if you're going to run it without a load, you better be quick about re-setting it to where it needs to be. or just do what I do and take a lamp fixture off one of your coin doors and get alligator clips out to attach to +5 and the COM/GND and you'll have all week to tinker with it.
 
first off, with a switching mode power supply, the other voltages besides +5 will show way off when no load is present. that's why I hook a coin door lamp up to power supplies if I'm testing them without a game hooked up. you can risk damaging the internals of the power supply running with no load.

second, I want you to consider how much power you lose between the power supply and boards that plug into that switcher. the power has to travel from the power supply, through the JAMMA wiring, to the pins in the JAMMA harness, to the edge connector at the switcher, then bounce around through some relays, and through more JAMMA "harnesses" (the slots on the 6-in-1 the games plug into) and then through your game boards. I don't know exactly why it was tripping the overcurrent protection, I mean, maybe that's what it's supposed to do, but the "solution" that you realized was that you weren't feeding it enough power when you consider all the stops along the way that voltage has to travel through.

I also strongly discourage using a cheap power supply with one of those 6-in-1 switchers. if it's an older unit, another reason the overcurrent protection can trigger is if the +5 adjustment is dirty. turning the knob back and forth a few times can clean it using the wiper inside, but you won't know what the +5 will be set at. so if you're going to run it without a load, you better be quick about re-setting it to where it needs to be. or just do what I do and take a lamp fixture off one of your coin doors and get alligator clips out to attach to +5 and the COM/GND and you'll have all week to tinker with it.

the power supply is a brand new one from suzo happ. One of those black ones. I must have not have had the power set high enough since I replaced it. When I replaced it, I only checked voltage at the PS itself and didn't check the end of the jamma harness. I didn't know it would make that much of a difference. Now I know. Just from the ps to the end of the Jamma harness I was loosing about 2 volts. I can only imagine that the switcher was trying to draw too much current and the power supply has some kind of overload protection so it doesn't strain itself and burn itself out if the load is too much. That is probably what happened here. I can honestly say I forgot about having a load hooked up to the PS when testing it. I do remember reading that in another thread but it just slipped my mind. I did make it quick while I was testing it and adjusting it though.

Either way I am glad it's working now. Now I have to level my pinballs and clean all my games. I am surprised that out of 6 games, despite being moved, they all are working. We all know how much games hate to be moved. Thanks for help too both of you.
 
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