Blow up boards, kill yourself. All kinds of possibilities.

LTG : )™

60vac on the rails. i don't think its the answer to your problems.

Think of ground as the first floor of a building. You're used to it and all is fine and dandy. Then you go to a different building and their first floor is also called floor one. Its generally the same thing, but in this case the two floors are at slightly different levels to each other. While both work fine, you're just relating the reference point to the ground floor which is different.

It comes down to the level at which the ground is at for your machine or the ground that your power coming out of your wall is at. By cutting off the ground plug, you're choosing a different ground level to work with.

it's kinda fun when you try to squeeze between two side by side machines to work on them and the ungrounded machine tingles it's way through your nether regions to the other machine.

So if a machine with the ground prong cut off has been working absolutely perfectly for years, there's no reason to think it will change if a new cord is properly installed, correct?

It hasn't been working perfectly. You've been lucky.

LTG : )™

Death by prong

No, the center prong is just a second path to ground at the circuit box. It's just for safety in case the standard white wire ground goes bad... That you don't become ground instead

Think of the ground as "protective earth". It is not a bucket to tip noise into.

If the AC power finds its way to a piece of earthed metal work then the easiest path for the power is via protective earth wire to the center pin. Fuse will likely blow and no pain for you. If there is no protective earth the metal just stays energised and when you touch it the potential difference means a lovely shock goes up your arm, through your heart and down out your toes...ouch.
Its a safety issue. fix it.

I touched some arcade parts once.

Felt my nuts shake & then the breaker flipped luckily.

I never did that again

Felt like I drank espresso afterward

Common side affects include but are not limited to "Electric shock" "death" "damaged electronics"

May induce a slight case of mild death. But other than that, you should be fine.

Chaos

just buy a 3 prong plug and replace it.or you will have a bad case of the frizzies. joe

Yeah. Just go to the electrical section of your local hardware store or Harbor Freight and buy a new plug to put on the end of your power cord.

The side effects of cutting off the ground prong:

If the game is on location, the Fire Marshall isn't going to be happy.

I think the ground part is covered.

As for the speaker hum. JP is a DE and DE machines are very prone to this. I've seen countless threads on thoughts to fix it but haven't really seen a solid answer to get rid of it. Part of the fun of owning a DE games I guess.

I think "death" needs to be listed twice.

If this thread included a poll asking what a new cord will fix/prevent, I think "Prevent premature death" would be the clear winner (with "Prevent your wife from collecting large life insurance payout" a close second).

I think a new cord is easily worth the time and expense. Definitely not something you want to mess around with, and I think the carriers of your home owner's insurance policy would agree.

Good luck.

That's for sure.

You can't even replace just the male end on the cord as a repair, or you get cited.

The entire cord has to be factory assembled.

When I bought my project Baby Pacman, someone had cut off the ground pin. Well, one of the first things I did was open the back cabinet door with the power on...if you've seen the back panel on a baby-pac you know there's a huge grounding plane on the door. Well I put my hand on that as I was swinging the door open and ZAP! It bit me pretty good.

It only does what was said above, Nothing else. Does not eliminate hum, etc, etc. Stereos and tvs have no ground, etc.

Only large mechanical devices use it where moving parts or something could fail and short to something the user is touching, etc.

How is it that EM's operate with no ground plug and no danger?

Designed to work that way is the short answer. The whole answer is too much for a forum post...

Jaz

Good enough.

I think they operate without it. But, no - danger!

If on location, don't put a new plug on the end, get a new molded plug and cord and wire it in right.

So snooping fire marshal and electrical inspector won't dig deeper.

LTG : )™

My williams fire! came with the ground plug cut off, clearly the previous previous owner didn't have grounding wherever it was being used. I swear when its' plugged in I get a slight tingle on the side rails. I've got a new linecord, just haven't installed it yet, but interesting to hear what the effects are.

When I first plugged in my Nascar machine and started playing it, whenever I would touch the metal lockbar I would get a little zap. As game play got more intense and I would learn on that bar harder, the zap got worse.
Best $3 fix I ever paid for.

Correct, they operate without it - because it does nothing when the device is working properly.

Wiki:
Earthing (grounding)
A third contact for a connection to earth is intended to protect against insulation failure of the connected device. When earthed distribution systems became common, earlier unearthed socket types were either replaced with new standards, or revised to include an earthing pin.

Interchange hazards
Occasionally, plug and socket combinations may allow power to flow but may not meet product standards for mating force, earthing, current capacity, life expectancy, or safety.

Just replace it. It costs like $3 at home depot.

I thought this about my T2 too...gone when I replaced.

How EXACTLY did you do this again?...

No problem as long as you continue to wear heavy rubber boots and gloves like the rest of us.

Dude do it right. You could kill yourself or some poor other fool who works on the thing.

because they didn't care back then... not to mention 3 prong grounded outlets weren't prevalent...

many of us ground our em's... with good reason...

stereos and tv's with 2 prong plugs are internally grounded, so they are indeed grounded... however, if they are connected to another device that is externally grounded, they then become susceptible to a ground potential difference, and trust me, you WILL get a speaker hum if that difference exists...

the second part isn't even worth addressing... the only difference between a (modern) two pronged appliance and a three pronged appliance is that the two pronged one is internally grounded...

Every pinball machine I bought had the ground prong cut off, that's the first thing I have to do is replace the cord.

EMs should be updated with modern safety 3 prong.

Green wire attached to the frame of the transformer.

This

electricute.gif

Exactly. I think.
Wait... what???

lol!

worlds collide

My Judge. Dredd will shock you if you put your arm on the side rail and use the same arm and touch the game next to it. I just went down to check the plug and it has a ground on it.

The shock I get is very slight tingle. Where should I look to fix this?

Receive enough mild shocks and your fingernails will fall off like Jeff Goldblum's did in the "The Fly."

Check that BOTH games have a ground pin.

Check the duplex outlet in the wall:

Meter on A/C

One probe in large duplex slot, one probe in ground hole (Hopefully 0v?) if 120v Neutral is HOT (thus wired backwards)

One probe in the SMALL duplex slot, one probe in ground hole (hopefully 120v?) If 0v, ground is open (not grounded)

Then check pins:

Open the high voltage box inside the pins. Be careful (or just have someone competent do this)

With the game off, but plugged in, check if your incoming blue wire is somehow hot with your meter.

So, meter set on AC:

One probe on blue wire, one on green. Voltage (hopefully 0v)? (if 120v blue is HOT)

One probe on brown, one on green. Voltage (hopefully 120v)? (if 0v, ground is faulty)

One probe on brown, one on blue. Voltage (hopefully 120v)?

In addition to what vid said, make sure that the metal in your game is actually connected to the ground lug. Basically, the ground braid in the cabinet is what connects every piece of exposed metal to the chassis/earth ground through the cord/plug.

Jaz

you forgot being sued in that list.

I've read that installing plastic washers on the board screws will help alleviate the hum in DE machines. I bought some to use on my LAH, but sold it before I got around to testing it out. Not sure if it was just for the sound board, CPU or driver or all three. There's some info. on it elsewhere here on the Pinside.