Wrong Power Line, poof........

Kyrosfear

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Gentlemen,
I only have myself to blame for this one.
I have a Midway cabinet that I got with a broken ground lead for the wall plug at the end of the cord. I changed the plug, but accidentally switched the the energized and neutral wires. Hit the switch and caused a ton of damage to my chassis. I fixed the plug and tested the cabinet. Everything else is working fine (e.g., pcb, power supply, etc.) and the voltages are all right. I have swapped out another chassis but before I hit the switch again I was just wondering if there is anything else that may have been damaged that I should check before powering it on. ( I definitely do not want to cook another chassis.) Thanks in advance.
 
Couple things come to mind:

1. if you just swapped the hot and neutral it wouldn't have done anything. You may have swapped the ground or something though which would be pretty catastrophic.

2. You didn't swap the monitor in this cab, did you? It sounds more like you've got a 'no isolation transformer' thing going on. I just did the same thing a few days ago.
 
I'm confused. It's AC power, what difference would switching the hot and neutral wires on a new plug make? If the ground wire stayed the same, then it would seem to reason it's not the new plug that caused your problems.
 
I'm confused. It's AC power, what difference would switching the hot and neutral wires on a new plug make? If the ground wire stayed the same, then it would seem to reason it's not the new plug that caused your problems.

I would think if you reversed them if anything it would shock you in some spots or something. lol

as for monitors that require isos though.. shouldn't matter, everyone on KLOV ever told me that isolation transformers remove the hot and neutral from the isolated side. :)
 
Yes but if you swap a monitor that needs an ISO into a cabinet that doesn't have one, when you plug it in it burns the monitor chassis up.

He said he plugged his game in and the monitor chassis burned up, so I was just asking if he swapped a monitor into the cabinet too.
 
Couple things come to mind:

1. if you just swapped the hot and neutral it wouldn't have done anything. You may have swapped the ground or something though which would be pretty catastrophic.

2. You didn't swap the monitor in this cab, did you? It sounds more like you've got a 'no isolation transformer' thing going on. I just did the same thing a few days ago.

1. That is what I figured, but that is all I changed. The game worked when I bought it, but the ground plug was broken off. I cut off the old plug and wired on the new one. Pic below of the new one on there.

2. "No" on the monitor swap. I am using a Midway power block and the K7000 in there was the one that was working when I bought it.

What kind of chassis damage happened?

K7000 buddy.

I'm confused. It's AC power, what difference would switching the hot and neutral wires on a new plug make? If the ground wire stayed the same, then it would seem to reason it's not the new plug that caused your problems.

That is what I thought, and the ground wire is still grounded on the plug. I am confused as well.


Thanks for all of the help guys. Here are some pics..... You can see two repairs I have already made to fix cooked traces on the traces. I still have some more repairs to do obviously.
CIMG1179_zpse52b2367.jpg

CIMG1184_zps485b4756.jpg

CIMG1185_zpsfdca00db.jpg

CIMG1186_zps3c9e2b69.jpg
 
I still can't tell by the picture of your plug that it's been wired correctly.

As far as the K7xxx is concerned, if you're sure that you wired the plug correctly, then I say the monitor chassis blowing up was purely coincidence. Especially if that K7xxx has a flyback with white knobs.

Unless your ground lead on the plug was accidentally moved to the hot side. That means you sent 120v up the ground rail, energizing your ground rails on the chassis, burning them up.

Or maybe something shorted inside the replacement plug when you buttoned it up? Moisture? Bare wire? Break in the insulation?
 
I still can't tell by the picture of your plug that it's been wired correctly.

As far as the K7xxx is concerned, if you're sure that you wired the plug correctly, then I say the monitor chassis blowing up was purely coincidence. Especially if that K7xxx has a flyback with white knobs.

Unless your ground lead on the plug was accidentally moved to the hot side. That means you sent 120v up the ground rail, energizing your ground rails on the chassis, burning them up.

Or maybe something shorted inside the replacement plug when you buttoned it up? Moisture? Bare wire? Break in the insulation?

Bad picture, for sure. But that was just to show you that the gound (green wire) was actually in the ground terminal.
 
I don't see an isolation transformer in your pictures. All I see is a power brick w/ an ATX power supply. I think LyonsArcade is on the right track. If there is not an isolation transformer, then there's your problem. The reason you didn't have a problem before is because the ground plug was broken. By fixing the ground plug, you now shorted your monitor to ground and "poof". Don't turn you machine on again unless your sure you have an isolation transformer. And, reversing the AC hot/neutral leads won't cause that kind of problem.
 
I don't see an isolation transformer in your pictures. All I see is a power brick w/ an ATX power supply. I think LyonsArcade is on the right track. If there is not an isolation transformer, then there's your problem. The reason you didn't have a problem before is because the ground plug was broken. By fixing the ground plug, you now shorted your monitor to ground and "poof". Don't turn you machine on again unless your sure you have an isolation transformer. And, reversing the AC hot/neutral leads won't cause that kind of problem.

Can't believe I missed that. Of course. Good explanation.
 
The isolation transformer (if the original monitor required one),along with a line filter, should be located in/underneath the gray box that the power supply is resting on. Where the power cord plugs in.
 
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The isolation transformer (if the original monitor required one),along with a line filter, should be located in/underneath the gray box that the power supply is resting on. Where the power cord plugs in.

u sure?. the isolation transformer would sit where that ATX style power supply is sitting. Under the metal box it's sitting on you'll find 2x fuse holders and an AC line filter normally.


also kyros be more specific when you say k7000, mostlikely that's a k7400 i'm guessing as it doesn't have an iso, any other k71xx series would require one and wouldn't last long sans iso.
 
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The isolation transformer (if the original monitor required one),along with a line filter, should be located in/underneath the gray box that the power supply is resting on. Where the power cord plugs in.

Jesus, I thought the same thing that this gentleman did. However, you guys were right, no iso. Damn, atleast now the cord thing makes sense. Thanks for the help guys and this is officially my first blown chassis because of no isolation transformer. Not a good feeling........
 
oh shit, I didn't see the picture. no, there is no isolation transformer underneath there lol

I made that mistake once. :) that guy's monitor still hasn't been fixed.

that design came along after a lot of the monitor manufacturers had models that came with switching mode power supplies (that didn't need isolation transformers anymore -- in fact they can be plugged straight into a wall outlet and I believe they can run on either 110VAC or 230VAC).

Midway either shipped with Hantarex Polos or Wells-Gardner U2000s around the time these cabs sprung up. that metal block literally takes the AC in to a line filter and spreads it to the two plugs on the top.

the previous models that did come with isolation transformers still (I think MK3 and KI were among the last ones) came with either the Polo or K7000.
 
I can't remember which games it was, but i have had 2 that had the iso tranny in that box. I only remember because i was shocked to find it when i stripped the cabinet for restoration,i picked up that power supply assembly and thought i was going to have a hernia because it was so heavy :) I pretty much have owned mostly midway dedicated games off and on for 10 years, so i know it had to be one of them. Perhaps it was a modification, but i know i had at least 2.
 
that sucks there was no ISO in there and the original owner of the machine was two cheap to install one when the monitor was replaced and took the lazy wrong way out to fix it.

good luck on the repair.

if you need help getting your chassis repaired shoot me a PM.

Peace
Buffett
 
To be honest with you Buffett, you will indeed see this chassis in the near future.
 
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