Earth connection
- Thread starter erzane
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DelsArcade
Enthusiast
Not quite sure what you are asking, but I'm guessing it's due to a ground loop which could cause interference in the sound or monitor signal.
https://www.bapihvac.com/application_note/understanding-ground-loops-application-note/
Del
https://www.bapihvac.com/application_note/understanding-ground-loops-application-note/
Del
the control panel should be attached to the metal frame of the cabinet itself. The purpose is to ensure that you don't get shocked by the control panel due to a difference in potential between the cabinet body and the control panel.
it really depends how your cab is wired but I believe the cab frames are typically setup to tie to earth BEFORE the filter:
for example here is the E29 diagram which shows it's setup exactly that way https://www.arcade-projects.com/threads/taito-egret-29-restoration.2009/page-3#post-35306
it really depends how your cab is wired but I believe the cab frames are typically setup to tie to earth BEFORE the filter:
for example here is the E29 diagram which shows it's setup exactly that way https://www.arcade-projects.com/threads/taito-egret-29-restoration.2009/page-3#post-35306
So, if Im referring to this : << I believe the cab frames are typically setup to tie to earth BEFORE the filter >>, the red sheme would be correct right ?
What bothers me - to take an easier example than the E29 diagram - is that the New Astros shema says there isn't any earth hooked to the noise filter.
What bothers me - to take an easier example than the E29 diagram - is that the New Astros shema says there isn't any earth hooked to the noise filter.
I just looked it up and the NAC absolutely has earth hooked up to the noise filter.
I've taken a screenshot and highlighted it in green for you.
To get back to the former topic, I'm rewiring my Pony 18 MK2 and I have some interferences on my monitor. Here is the current wiring I did where earth corresponds to the black shema (see 1st post). I tryed many ways (red and black way) but still interferences. Regarding this very low resolution shema of the Pony 18, it seems that earth is going into the noise filter then straight to the cabs terminal lug. I did it that way but the interferences still persits. Btw, the Pony 18 does have a 110/220 internal transformer like the european NAC, which probably explains why the earth is going into the noise filter too.
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it doesn't matter. the earth ground doesn't pass through the filter. it simply connects to the housing of the filter.
So there is no "ground before the filter" vs "ground after the filter" it's the same.
So there is no "ground before the filter" vs "ground after the filter" it's the same.
In my shema the earth is connected to the filters housing as you say so it should be ok that way but my issue still persists.
Btw, I tried to restitute a good quality shema of the Pony 18 wiring. Maybe can you help me to findout where my issue come from and where are the mistakes in that shema restitution compared to the original one (if you can read it - the resolution is quite small) ?
Btw, I tried to restitute a good quality shema of the Pony 18 wiring. Maybe can you help me to findout where my issue come from and where are the mistakes in that shema restitution compared to the original one (if you can read it - the resolution is quite small) ?
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I know it's a different cab but there is a schematic for the Pony II 28: https://wiki.arcadeotaku.com/images/f/fa/Jaleco_Pony_MKII_28_Manual.pdf
I don't think adding an earth ground is going to do much to fix the noise in your monitor.
In fact, most monitors (that Pony II 28 included) aren't attached to earth ground at all.
I In my DDR cab I had to disconnect the earth ground from the monitor frame to clear up noise.
noise can also be from the video input harness as well, if that has poor connectivity (especially poor connectivity on the video ground) or if those wires run along side some power wires for too long of a distance both of those things can induce noise. noise can also come from bad connection or interference on your remote board (if it has one)
I don't think adding an earth ground is going to do much to fix the noise in your monitor.
In fact, most monitors (that Pony II 28 included) aren't attached to earth ground at all.
I In my DDR cab I had to disconnect the earth ground from the monitor frame to clear up noise.
noise can also be from the video input harness as well, if that has poor connectivity (especially poor connectivity on the video ground) or if those wires run along side some power wires for too long of a distance both of those things can induce noise. noise can also come from bad connection or interference on your remote board (if it has one)
Thanks for your Pony28 shema. I guess this should do the job. I guess there is no big difference between these Pony setups so this shema will be helpfull.
I see. I'll try to take the monitor off to see if the noise is till there once out from the cab. But maybe the issue comes from the remote control I did to deport two pots on another pcb.
I see. I'll try to take the monitor off to see if the noise is till there once out from the cab. But maybe the issue comes from the remote control I did to deport two pots on another pcb.
Edit : I've taken the monitor off from the cab and the issue dissapeared.. All is fine, the image don't move and it's crystal clear, no interferences. The problem appears only when the monitor is mounted inside the cab. Seems to be an insulation issue but I think the earth is well connected :
1. An earth cable is going from the PSU earth lug to the cabs lug. Another earth cable is going from the same PSU earth lug to the CP. A third earth cable is going from the Noise filter to the cabs lug. Anyway, I tryed to disconnect the earth from the CP and the earth from the noise filter but the issue is still there if the monitor is mounted inside the cab.
If I'm refering to both Pony 18 / 28 shemas, The earth is hooked to the GND (Jamma B). Why hooking an earth to the GND ? Ive never seen this before... Maybe the earth wire is connected to Jamma B per convenience to be leaded to the CP more easily but I don't understand why this earth should be connnected to GND A ; 1 ; 2...
Edit : I just thought about smt : I have off-spray painting all around inside my cab and also where the earth terminal lug screw is. Maybe the problem comes from the fact that the earth cable is stopped/insulated by the painting... Maybe that's the problem... But in that case, how is it possible that the monitor reacts to the ''A'' parts once mounted inside the cab since ''A'' parts are also painted (with mate painting, which is maybe more insulated than the off-spray) ?
Edit : Another thing : on the Pony 18 shema, there is a 110/220 transformer (which is missing from The Pony 28. But the Pony 18 (even it's a japanese version - btw my low res. shema is taken from Yahoo) do have a Toyozumi (ex Toyoden) 110/220 transformer and it seems that an earth is also hooked there (I highlighted it in green). Does it mean that this earth should be hooked to the leg of the transformer or to a screw terminal lug which I don't know which one would it be... ?
Thanks for your help and analysis.
1. An earth cable is going from the PSU earth lug to the cabs lug. Another earth cable is going from the same PSU earth lug to the CP. A third earth cable is going from the Noise filter to the cabs lug. Anyway, I tryed to disconnect the earth from the CP and the earth from the noise filter but the issue is still there if the monitor is mounted inside the cab.
If I'm refering to both Pony 18 / 28 shemas, The earth is hooked to the GND (Jamma B). Why hooking an earth to the GND ? Ive never seen this before... Maybe the earth wire is connected to Jamma B per convenience to be leaded to the CP more easily but I don't understand why this earth should be connnected to GND A ; 1 ; 2...
Edit : I just thought about smt : I have off-spray painting all around inside my cab and also where the earth terminal lug screw is. Maybe the problem comes from the fact that the earth cable is stopped/insulated by the painting... Maybe that's the problem... But in that case, how is it possible that the monitor reacts to the ''A'' parts once mounted inside the cab since ''A'' parts are also painted (with mate painting, which is maybe more insulated than the off-spray) ?
Edit : Another thing : on the Pony 18 shema, there is a 110/220 transformer (which is missing from The Pony 28. But the Pony 18 (even it's a japanese version - btw my low res. shema is taken from Yahoo) do have a Toyozumi (ex Toyoden) 110/220 transformer and it seems that an earth is also hooked there (I highlighted it in green). Does it mean that this earth should be hooked to the leg of the transformer or to a screw terminal lug which I don't know which one would it be... ?
Thanks for your help and analysis.
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I think disconnecting individual items from the earth ground in your cab is going to be largely irrelevant. The only device that MIGHT cause noise is the PSU digital ground tied to earth ground. But the CP and other stuff is just dumb hunks of metal and isn't going to make a significant difference.
It's also possible that the earth ground in your house is not clean and has noise which is why the monitor reacts poorly when grounded. you could try using an AC cable for the whole cab without earth ground. If nothing else it would be worth testing this to rule it out.
if you've ever seen a PC then you've seen this before. all of the screw posts on a PC motherboard are tied to digital ground and tied to the metal case of your PC, which is then tied to the earth ground post of the AC cord.
you can easily check this with a multi-meter. Realistically you should make sure that ground terminals a re free from paint, but in general that paint would need to be super thick and well coated for the screw teeth on the binding post to not cut through it.
The transformer would only be equipped in regions that use this transformer. Most of Japan uses 100V so a transformer would not be equipped. even then every transformer is different and you should hook it up however it's designed to be hooked up. Some have an earth ground some don't. But in my experience it's much like the AC filter where it's just the frame of the transformer that's grounded and it doesn't really have an impact on anything.
<< ...PSU digital ground... >>
- You mean the GND ? So inside the PSU, the GND is hooked to the earth ? Ok, didn't know that. I'm a noob in electronics haha. But I never have seen any Jamma loom having an earth hooked to the GND. Am I right ? Even on the New Astro the Jamma loom don't have any Earth...
Maybe the Ponys shema shows some bridge connections there but does it mean that both GND and Earth should be bridged with a soldier gun at that point of the Jamma loom on a Pony ? Maybe it only means that both are connected at the origine inside the PSU as you said. I thought that the earth wire going to ''B'' posi. of the jamma looms was only there as a convenience to get the wire across easily and rely the rest of the harness then go to the CP.
<< ... you could try using an AC cable for the whole cab without earth ground... >>
- Does it mean that I can unhook from the cab earth terminal lug both earth wires coming from the main AC cable and the PSU without suffering from any damages ? Btw, in Switzerland we have three wires inside an AC cable as a blue, a brown and a yellow/green (earth). So if you confirm I'll disconnect the earth wire from the main AC cable and the PSU then I'll try that way.
<< ...paint would need to be super thick and well coated for the screw teeth on the binding post to not cut through it. >>
- That's right, I forgot the binding post. So I guess this topic is resolved
<< ...But in my experience it's much like the AC filter where it's just the frame of the transformer that's grounded and it doesn't really have an impact on anything. >>
- So I can hook an earth ring terminal to one of the screw holding the leg of the transformer to check right ? Btw, I can't see any place designed to hook an earth wire on this transformer. Here is a similar model :
https://www.toyozumi.co.jp/products/ad21/pdfs/AD21-200A2.pdf
- You mean the GND ? So inside the PSU, the GND is hooked to the earth ? Ok, didn't know that. I'm a noob in electronics haha. But I never have seen any Jamma loom having an earth hooked to the GND. Am I right ? Even on the New Astro the Jamma loom don't have any Earth...
Maybe the Ponys shema shows some bridge connections there but does it mean that both GND and Earth should be bridged with a soldier gun at that point of the Jamma loom on a Pony ? Maybe it only means that both are connected at the origine inside the PSU as you said. I thought that the earth wire going to ''B'' posi. of the jamma looms was only there as a convenience to get the wire across easily and rely the rest of the harness then go to the CP.
<< ... you could try using an AC cable for the whole cab without earth ground... >>
- Does it mean that I can unhook from the cab earth terminal lug both earth wires coming from the main AC cable and the PSU without suffering from any damages ? Btw, in Switzerland we have three wires inside an AC cable as a blue, a brown and a yellow/green (earth). So if you confirm I'll disconnect the earth wire from the main AC cable and the PSU then I'll try that way.
<< ...paint would need to be super thick and well coated for the screw teeth on the binding post to not cut through it. >>
- That's right, I forgot the binding post. So I guess this topic is resolved
<< ...But in my experience it's much like the AC filter where it's just the frame of the transformer that's grounded and it doesn't really have an impact on anything. >>
- So I can hook an earth ring terminal to one of the screw holding the leg of the transformer to check right ? Btw, I can't see any place designed to hook an earth wire on this transformer. Here is a similar model :
https://www.toyozumi.co.jp/products/ad21/pdfs/AD21-200A2.pdf
I'm not saying it's common on JAMMA looms, I'm simply saying lots of electronics do this. so when you see the diagram for the Pony shows that it's connecting them, it's not surprising.
in the USA older building are often missing the ground pin on AC cables so it's not uncommon for people to rip that prong off of an AC cable to make it work in older buildings. I suppose you could disconnect it inside the cabinet for the same effect. I wouldn't be surprised if in your country you can find a "3 prong to 2 prong adapter" they're quite common here.
I have no idea, I don't know how that transformer is constructed so I can't give you advice on it's proper use.
So I removed the earth (all earth) and all is fine now
I didn't know that earth stuff. Btw in Switzerland we all have a three prong connector in every home. We have adapters also yes.
So, if I understand well, if in a country or a home there is earth already since three prong connectors on the wall, arcade cabinets don't need earth connected anywhere ? Same for the New Astro ? I'm mounting my New Astro btw and I already wired all the earth cables. Does it mean I can litteraly get rid of them ? Ps. the NAC does not have any internal transofrmer, all is 110V inside, including the AC cable so I'll use an external japanese Nysso 110/220 transformer with a two prog connector (I asked to the company to make it like this since it's a service they gives to the customer so he can choose the connector type).
I didn't know that earth stuff. Btw in Switzerland we all have a three prong connector in every home. We have adapters also yes.
So, if I understand well, if in a country or a home there is earth already since three prong connectors on the wall, arcade cabinets don't need earth connected anywhere ? Same for the New Astro ? I'm mounting my New Astro btw and I already wired all the earth cables. Does it mean I can litteraly get rid of them ? Ps. the NAC does not have any internal transofrmer, all is 110V inside, including the AC cable so I'll use an external japanese Nysso 110/220 transformer with a two prog connector (I asked to the company to make it like this since it's a service they gives to the customer so he can choose the connector type).
no electronics "NEED" it. it's optional.
Typically earth ground can improve safety, because a short inside the electronics can go to ground instead of something else. And it can reduce noise; if the earth ground in the house is properly grounded
it seems however that the earth ground in your house is not properly grounded and is generating noise rather than removing it. :/
IMO it's better to have ether ground, but it's not required. And you might consider hiring an electrician to inspect the grounding in your house.