Transformer interference in cocktail games?

[2PacMan]

Has anyone ever heard about this.  The guy at the repair store said the transformer located under the monitor was causing interference, thus making my game have light vertical scrolling lines in the screen.  I'm assuming the transformer is under the metal plate that says "do not remove".

Can i just lay another piece of metal on top of the metal cover for additional sheilding, or will that damage the game??

Anyone else have this problem?  When i open the game up, and the monitor is away from the inside of the cab, the wavy lines go away. ..it's a cocktail by the way.

[HaRuMaN]

try taking a piece of tinfoil and covering the power supply with it

[RayB]

Since the table was designed that way, I'm wondering if there isn't perhaps some other issue, such as the grounding's broken or the voltage is no longer stable...?

[2PacMan]

Well, it looks like whoever owned the game before me fiddled with that metal plate cause it was all bent up.  I tried to bend it back and re-screw it down, but it's still up in a few areas...can i wrap that box area in tin foil??  Does the thickness of the cover make a difference, or does the whole area just need to be sheilded?

I could try covering the power supply....where exactly is that inside the machine??

I just had a new grounding plug installed on the end of the machine, so hopefully that's not the problem.

[HaRuMaN]

The transformer is part of the power supply...  any thinkness of tinfoil should be fine, as long as it covers it completely.  Just make sure you don't cover any up any fans.

[ChadTower]

Remove the broken shield and put a coffee can over the transformer.

The interference could also be coming from the PCB.  If the coffee can doesn't work, swap out the PCB with a different game and see if it goes away.

[RayB]

Check where certain wiring is going......

[fredster]

I have an Arkanoid cocktail that's doing something like that to me.

It's in a nintendo (like a donkey kong) cocktail.  It has lots of issues like that.

1) It's a WG 4900, it has no mental shield around the monitor
2) It has this HUGE transformer in it
3) The PCB is mount directly under the monitor

I was looking at the pacman cocktail I have.  It works okay. The PCB is on the side away from the G07 it has. The G07 has a bigger metal shield around the monitor. I put a piece of aluminum foil around a box and put it over the transformer of the Arkanoid, no dice.

Randy Fromm says that the monitor mounted like that will be more prone to the magnetic field of the earth too.

I haven't found a cure for this puppy yet either.  The monitor was fine when it was in an upright. I mounted a brand new kortek like this and didn't have an issue with it. I didn't have to use the isolation transformer on it, but I did anyway since it was there.

[2PacMan]

Well, i did a little work on my game last night.  I took off the metal sheild and hammered it out straight again, and screwed it on tight....still no dice.  So i tried the aluminum foil trick...it still didn't work.  The transformer is well sheilded now, so it must be something.

The guy at the repair shop said that's just the way these things were made back then, he had no idea how to fix it without doing serious investigative work.  After last night, i've decided just to live with it.  It's not that bad, and i don't want to risk breaking my game again...unless anyone else has some other quick fix ideas?

[ChadTower]

Try shielding the wiring.  It should be a simple job of just wrapping foil around it... easily removable if it doesn't do anything positive.

[SirPeale]

You sure your screen control isn't up too high?  Try turning it down a smidge.

[2PacMan]

Which wires should i wrap??  Just every wire I see, or are there certain ones?  Also, do i need to be careful about what i touch with the tinfoil....i unplug the machine, but i heard the monitor still holds a charge...will i get shocked if i touch the wrong thing with the tinfoil...can i cause damage if i turn the machine back on and the foil is touching something wrong, like the transformer or monitor??

Which screen control should i adjust....like the brightness or the color??  There are a couple of dials under my game, most just make the screen brighter or fuzzier or more reddish...but don't seem to affect the lines any.

[ChadTower]

Which wires should i wrap??  Just every wire I see, or are there certain ones?  Also, do i need to be careful about what i touch with the tinfoil....i unplug the machine, but i heard the monitor still holds a charge...will i get shocked if i touch the wrong thing with the tinfoil...can i cause damage if i turn the machine back on and the foil is touching something wrong, like the transformer or monitor??

If you don't know what things to touch and not touch on your monitor, you should get your hands the hell out of a cocktail cabinet.  It's too cramped in there to not know what the dangerous parts are.

[SirPeale]

Which screen control should i adjust....like the brightness or the color??  There are a couple of dials under my game, most just make the screen brighter or fuzzier or more reddish...but don't seem to affect the lines any.

Chad's right.  But...I'm talking the coarse SCREEN adjustment.  Should be a pot on your flyback.

[ChadTower]

Chad's right.  But...I'm talking the coarse SCREEN adjustment.  Should be a pot on your flyback.

And half a foot from 20000 volts of angry electricity.

[RayB]

Maybe this is just an issue with age...
Last auction I attended there was a Donkey Kong JR cocktail table, and the ISO transformer was mounted OUTSIDE of the cab! (bolted to the bottom).

[ChadTower]

Probably moved there because the tech wasn't good enough to figure out the real problem.   

[SirPeale]

Chad's right.  But...I'm talking the coarse SCREEN adjustment.  Should be a pot on your flyback.

And half a foot from 20000 volts of angry electricity.

Didn't I already say you were right?

[ChadTower]

And half a foot from 20000 volts of angry electricity.

Didn't I already say you were right?

Not directed at you, repeated for emphasis in case this person doesn't get it.  He's already sticking his hands in and around and moving metal parts inside a cramped machine knowing of lethal voltage in it but not where...

[2PacMan]

Well, i'm opening the machine...so it's not as cramped as you make it sound. 

I already shocked myself when i first got the game, cause i had no idea the monitor held a charge.  I got a good zap and a burning sensation on my hand for a day.

Like I said, i'm new to this owning and fixing arcade games...i just got my first one like a month ago, so i'm just relying on some experienced people on this board to help me out...that's all.

[ChadTower]

I already shocked myself when i first got the game, cause i had no idea the monitor held a charge.  I got a good zap and a burning sensation on my hand for a day.

And you put your hand back in without knowing anything about why?  Doing it once is a stupid error... doing it twice is Natural Selection.  Close the cabinet and do some reading about monitors.  Don't open the cabinet again until you can explain to someone else how to discharge a monitor safely.  This is not a joke.  You are playing with your life here and you clearly don't respect the fact that this thing could kill you.

[2PacMan]

Well, i know well enough to stay away from the monitor now.  I fiddle with other things, but i don't get involved with the monitor at all, cause i don't know much about it.

[ChadTower]

You do know there is electricity in the other parts too, yes?

[2PacMan]

Care to elaborate??  If you would like to give helpful advice, i'm open to it...i'm new.

But....if you are just going to keep telling me to leave my game alone and don't give me any info, that's not helping.

I don't want to make any enemies here, i just want some constructive advice on games, that's all.

[ChadTower]

The best advice I can give you is to pop onto Google, find some good arcade repair primers, and read them.  Then read them again.  I said that before and it is the best advice we can give you.  I'd give you a really good source, but it seems to be down right now, and I have a feeling it's not coming back.

http://randyfromm.com/amusements/techdept/

That top link into the secret dept, if it comes back, read it ALL twice.  That's the very best advice you're going to get.  Study and read and learn.

[2PacMan]

Thanks...that site had some pretty good info.  The top link was still down, but i got some good info from the other links.

Thanks again

[Stingray]

The first thing you need to learn is how to safely discharge your monitor. That part is pretty much essential. Chad isn't jerking you around, there's lethal voltage lurking around in there. Do a google search on that topic and read up on it.

-S

[RayB]

... Yeah but you don't discharge a monitor if all you're doing is twiddling the pots. What he needs is to 1. Open the cab up properly so he has as much access to the pots as possible, and 2. Buy a plastic screw driver.

[ChadTower]

Uh, no, you don't stick your arm in something if you don't know where the teeth are.  You just don't.

BTW, I like the idea of jerking and lurking.  It just sounds right.

[Silhouette]

I had some transformer problems with a Pac-Man cocktail. I was on the 2nd Pretzel level, and then Megatron just kicked the machine and it shut right off. That guy's a real ass.