Minor electric shocks from Stargate

dahnz

New member
Joined
Oct 18, 2008
Messages
303
Reaction score
2
Location
na, New Zealand
Hi all

I have a Stargate that had a switching power supply installed in it and I seem to be getting minor electric shocks from certain metal parts (eg, the on/off switch, the coin door, and the shaft of the joystick). I say 'seem' because it is possible it's my imagination - they're not of the order of magnitude that leaves you in no doubt whatsoever. Does anyone have any suggestions as to what could be causing this and what I should be looking for?

I'm not in the States, so the switching power supply is being run off a transformer that steps down the 230v to 110, if that makes any difference.

Many thanks, Dominic
 
you need to recheck your ac hookup...

all the metal parts of the game shoudl have a ground wire attached(its usually a green wire). Follow that all the way back to where the power cord comes in... make sure that is grounded to the ground terminal on your power cord. Bieng your not here in the states, unfortunately you may have to get a little creative with your ground hookup...
 
Thanks. I'm at work at the moment, so I'll check it tonight. I know it still has the grounding wire running through the whole cab (everything seems to be original, except for the addition of the switching power supply), and the plug from the cab to the external step-down transformer is a three pin (grounded plug). However, the plug from the transformer to the power supply is only two pin. Would this have any relevance? (I'm sure you can tell I'm a novice at electrics.)
 
actually stargate will have braided wire connecting eveything. joystick to control panel bolt. Wire is stapled to the side of the cabinet and coin door and monitor attach to the braided wire. It all end up at the isolation transformer/line fliter where it meets with the ground pin from the AC cord. Make sure the ground pin is not broken off the ac cord. .

In your case check to see if that step down transformer originally had a ground pin. If it did, you need to fix that.
 
Make sure that your house wiring is correct and that hot and neutral are not swapped. I had a pac-man plugged into a room that had been illegally wired by the previous homeowner without a permit and inspection, and among numerous other errors, they swapped hot and neutral on every outlet. Game ran but you got quite a jolt from the coin door and control panel if you touched them just right.

Buy one of those 3 neon bulb circuit testers to be sure, or use a multimeter and figure it out yourself. Sometimes homes have a floating ground that carries a tiny ac charge with respect to true ground. In any of these cases -- get it fixed as it could hurt more than just your machines.
 
This is God's way of telling you that you should never play Stargate. It was made by the Devil to coerce players into thinking it was fun because it was a "game", when in reality it is a diabolical damnation that should be driven from your home with a crucifix and holy water.

There's a reason why the cab was painted with the red and yellow flames of Hellfire....
 
This is God's way of telling you that you should never play Stargate. It was made by the Devil to coerce players into thinking it was fun because it was a "game", when in reality it is a diabolical damnation that should be driven from your home with a crucifix and holy water.

There's a reason why the cab was painted with the red and yellow flames of Hellfire....

Friggin hilarious!
If there isn't a "Best of KLOV", then we need to start one!
 
This is God's way of telling you that you should never play Stargate. It was made by the Devil to coerce players into thinking it was fun because it was a "game", when in reality it is a diabolical damnation that should be driven from your home with a crucifix and holy water.

There's a reason why the cab was painted with the red and yellow flames of Hellfire....

Wow -- he better ship that game to you right away so you can cleanse it of its evil.

Do you have a standard rate for that?
 
This is God's way of telling you that you should never play Stargate. It was made by the Devil to coerce players into thinking it was fun because it was a "game", when in reality it is a diabolical damnation that should be driven from your home with a crucifix and holy water.

There's a reason why the cab was painted with the red and yellow flames of Hellfire....

So tell me there mod... Your 1 ship Stargate high score: Hundreds, Thousands, Tens of or Hundrends of Thousands?

1 ship score because, of course, any accomplished player could play a single Stargate game for as long as he[she] could remain standing.

Saltbreez
 
... should be driven from your home with a crucifix and holy water. ...

Does simple green and a water hose count? Mine has been baptized at least once.

Um, ... well... At least the upright has been. [which might explain the furniture moving around in the living room]

Saltbreez
 
It's not grounded. I bet your plug is missing the grounding pin, the pin is falling off, the ground wire isn't connected or the grounding braid isn't connected properly. Happens all the time...
 
Actually, I don't think Stargate is the work of the devil - I think it and Defender were part of the alien invasion conspiracy, softening us up for the idea of aliens abducting humans and turning them into alien-human mutant hybrids. It followed on from similar concepts expressed in the British 1960s TV series "UFO" and presaged the whole "X Files" oeuvre.

But, anyway, back to the issue in hand. I checked the wiring and the braiding is complete and attached to all relevant metal parts (joystick, coin door, marquee light fitting brackets, etc), and at the bottom of the cabinet it is connected to one end of the line filter and continues at the other end of the filter to the transformer.

From the power in lead, one wire goes to the fuse then back to the end connection of three on the side of the line filter, the green (earth?) wire goes to the middle conenction of the three on the filter, and the last wire goes to the third connection on the filter. In other words, it all looks as per the wiring diagram and as per my Robotron.

The only thing I noticed is that the green wire from the internal power socket is not connected to the same terminal on the filter as the green wire from the power in - instead it appears to be connected to the transformer end of the filter, along with the braid, but again this is the same as on my Robotron and I presume there's a good reason for this.

However, the power-out plug from the external step-down transformer does not have an earth pin - there is an obvious clip arrangement where a pin could be inserted, and there are earth clips on the top and bottom of the plug. It looks like the Type E / F hybrid on http://en.wikipedia.org/wiki/AC_power_plugs_and_sockets .

So, is this the likely issue? If so, why has it not been a problem on my Defender, which does not even have an earth pin on the power cord?

By the bye, I did get out the multimeter and it looked like there is about 30V on the metal parts - just enough to give me a nice jolt when I'm desperately twisting the joystick and my fingers connect the shaft.

Finally, thanks for all the help so far. I have a few problems with these games (they've been in storage for a few years), so once this is sorted I'll be back with further questions.

Dominic
 
Any other hints? I've checked the braid, the wiring looks okay, the earth pin is present and not falling off, and I've ruled out the external transformer plug. I'm a bit stuck and there are no handy arcade techs around here I can call on for help.
 
Have you actually put a meter to it? You will of course have to come up with a way to hook one probe to earth ground.

Or you take off your shoes, and stand in a puddle of water, and see if that increases the shock. :D

What kind of step down trans is it? Can you send pictures?

Is it one of those large bricks that plugs into the wall, and then has a plug on it for the 115?

It's got to have something to do with the switcher and the Step down.

The monitor uses a iso transformer, are you getting shocked when touching the monitor frame as well? You will of course have to be in the back of the game.
 
When you say "put a meter to it", do you mean the cabinet? If so, yes, I put one lead on the joystick shaft and one on the coin door of my adjacent Defender (which has never given me shocks and appears to be correctly earthed) and it read 30V as soon as the game was plugged into the external stepdown (from 230 to 110), even without turning the game on.

I can send pictures, but it will take a few days, 'cause I'll have to borrow a digital camera, but it's a heavy black beast, commercially made in Japan as I recall (I'm at work at the moment), which plugs into the local 230V and has two 110V outlets on the front.

I haven't tried touching the monitor chassis yet, but given that every other metal bit I've so far come into contact with has shocked me, I would say it's a fair bet that it would have a charge too.

And thanks again, I really appreciate the help.
 
... I put one lead on the joystick shaft and one on the coin door of my adjacent Defender (which has never given me shocks and appears to be correctly earthed) and it read 30V as soon as the game was plugged into the external stepdown (from 230 to 110), even without turning the game on. ...

That is one major clue! Go back to the suggestion about standing in the water... Oh never mind...

Good luck,

Saltbreez
 
Yeah you've got definate grounding problems. It could be the Step down transformer has a bad ground internally. How hard would it be to swap the trans out with your other game?
 
I only have one step-down transformer which I use for both the Defender and Stargate, but I've not had an issue with the Defender's grounding. They're not cheap down here (New Zealand), so I wouldn't want to buy a new one unless I was sure it was the problem. (This is not a transformer that came with the game or that has anything to with arcade games - I needed to run the games on local voltage, so I bought the step-down separately.)
 
Back
Top Bottom