mrs.pacman

coinopjunkie

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I have an all original (Except two bits multi pak board add on) mrs pacman in my garage game room works near perfect alone but turn on another game next to it and the screen gets issues with the first neighbor a computer type power supply the screen would jump just a little enough to give you a head ache but not that obvious I then switched it for a new neighbor a new switching style power supply and now it kind of rolls. any ideas I tried conditioning the power line with no change.
 
Though I'm sure you've already done so, make sure your switching power supply isn't set too low. Most are set at exactly +5v. Pac-Man boards expect up to +7v input as the board itself down-converts the incoming voltage to the +5 it needs. I generally crank up the adjustment knob on switching power supplies going into Pac cabs to as close to +6v as it will go to ensure it never falls below what is expected. If your switcher is outputting anything below +5 it will cause intermittent issues.

I would almost wager a bet on the above being your solution. When you power on your other games it is probably draining supplied power to your circuit just enough to cause problems.

It sounds like your wall receptacle is straining with too much plugged into it.
You could also correct the issue by adding a second breaker to your breaker box and dedicated lines specifically for your arcade games, but if you aren't experienced in doing so, that can be costly.

Try the above and see if it helps...if not, post a few pics or a quick vid so we can get an idea of what you are seeing.
 
Also just to clarify...
Your monitor is connected to a dedicated separate isolation transformer and not directly to incoming wall power correct?
 
clarification

the mrs pacman is not the switching power supply, its the game next to it, i tried two different games with different power supply's next to it and both cause problems but differant problems. the mrs pacman is original power supply. if the game next to it is turned off mrs pacman is fine if you turn on a game next to it it has problems does not matter if same circuit or different circuit same thing. I wired my garage for an arcade there is like 4 or 5 differant breakers in the garage. its no strain.
 
One of the ms pacman I am working on is sensitive to the EMF and RF waves from other devices. I going to try to install a bob roberts cap kit and see it cures the sensitivity to noise. I am thinking that C7 and C8 or C5 might be drying out.

Since I got a stack of parts and 2 games. I am in the process of tracking down why one is so sensitive to noise while the others are not.
 
cool let me know

Let me know if you find anything out I really don't think it is a monitor cap, but what do I know. I'm thinking some type of missing shielding or something I was told this monitor was recapped when I bought it but that was before I even knew what that meant. it was my first arcade game. It does work fine with out any other games on near it although my slot machines next to it don't bother it. Video poker. I had another pacman next to it that didn't bother it but I killed it so I can't try it now.
 
maybe i found it

as I was typing my last reply I thought of something, i have been working on a lot of go7's lately and when i mentioned shielding i didn't recall seeing the metal case that goes around the tube on the go7 is this shielding it is missing off this monitor in the mrs pacman I wonder why someone would take that off. Is that my problem?
 
more problems

So I went and pulled the go7 out and looked at it better it is an rca tube looks to be the right tube but I have never seen a go7 tube with out the shielding but this one never had it to begin with so, since I already had it out I switched the tube anyway to one with the shielding put it in with the original chasie and everything looks good except the bottom and top are pulled in. Right side upper and lower if looking at the monitor mounted vertically in the cab. I know on computer monitors there were pots to adjust this but I don't see any on the go7. Funny thing is it was quite noticeable where I was working on the machine but not that noticeable when the machine went back to its home. I wonder if this chasie is ready for a rebuild or my garage has some funky stuff going on.
 
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