Sigma Raijin and Irem M92 ground leak

[Green beret]

Using Sigma Raijin control box with Irem's M92 boards causes wavy image when someone touches the meta casing of the Raijin or the volume control of the M92 or the cap next to it.
Image is clear if you only touch the plastic buttons and the joystick. This issue doesn't happen with other boards like capcom or SEGA. But I have not a clear image using Atomiswave too. Maybe it is related.

I will update with pics from the PSU and Jamma fingerboard.

Please system11 move the posts about this issue from the M92 capacitors leaking thread. Sorry for that, I thought all these were connected together.

[Green beret]

Normally the metal housing of the Sigma should not touch the PSU directly. There should be an isolation between them.
I will try playing wearing plastic or wooden gloves.

[Green beret]

Here are some pics from the inside
[https://imageshack.com/i/ipLK2kTDj
https://imageshack.com/i/id4bDyzkj
https://imageshack.com/i/ex945EAVj
https://imageshack.com/i/ipsTYIpPj
https://imageshack.com/i/exT3aRPOj
https://imageshack.com/i/exJRkAcYj
https://imageshack.com/i/idjONhaij
https://imageshack.com/i/pdzxf0Ofj

[brokenhalo]

Please resize your pictures.

Looking at what I can see, the power supply and the jamma harness don't appear to be grounded. Is the power plug a grounded type plug (2 prong or 3), and what country are you using this in (step down transformer?)?

[Green beret]

Please resize your pictures.

Looking at what I can see, the power supply and the jamma harness don't appear to be grounded. Is the power plug a grounded type plug (2 prong or 3), and what country are you using this in (step down transformer?)?

Hi,
The plug is a Japanese 2 pong. I am using it in Greece220-240volts. Even if I switch it to 100v and connect to a step down converter, waves are still there if I rest my hands on the metal housing.

[SuperDeadite]

Japanese 2 prong plugs don't have a ground. Connect a wire to the case and send it to a proper ground. The Raijin may have a screw terminal for adding a ground wire on the back (as this is the standard Japanese way), but I honestly cant remember if it does or not.

[Green beret]

Japanese 2 prong plugs don't have a ground. Connect a wire to the case and send it to a proper ground. The Raijin may have a screw terminal for adding a ground wire on the back (as this is the standard Japanese way), but I honestly cant remember if it does or not.

Shall I desolder and remove the Japanese jack and connect a euro plug with ground? Ground of the new cable shall go on the psu screw terminal where it says ground? I can't tell if there is a screw terminal for adding a ground wire...Where might it be lockated?

[mvsfan]

what kind of jack does it have on the back? that might be an IEC jack in wich case you can just buy another Euro cord for it.

Ive bought multi volt electronics from elsewhere that used an iec jack and all i had to do was buy a U.S. cord for it and switch it to 110.

[Green beret]

what kind of jack does it have on the back? that might be an IEC jack in wich case you can just buy another Euro cord for it.

Ive bought multi volt electronics from elsewhere that used an iec jack and all i had to do was buy a U.S. cord for it and switch it to 110.

Here is the back of the Raijin
https://imageshack.com/i/idAbHv27j

[rtw]

@Green beret, Thank you for creating a new thread

Please do something with the size of the images!

I have experienced wavy lines because of ground-loops.

There are two kinds of ground in your arcade cabinet / super-gun: GROUND and 0V.

Your typical PSU will have 0V (COM / GND) and FG (FRAME Ground / Ground symbol)

The 0V should be wired on both sides of the JAMMA loom i.e. 1,2,A,B,27,28, e & f should all be 0V.

Your JAMMA connector is not populated correctly, you are missing 0V on 27,28, e & f

Check the correct pinout here:

http://www.jammaboards.com/jcenter_jamma_pinout.html

To avoid ground-loops I connect FG and 0V together on the PSU.

So this is what I would try first:

Connect two wires from the free GND tracks here: http://imageshack.com/i/idjONhaij to pin 27,28, e & f on your JAMMA connector.

Connect a wire on your PSU between FG and COM.

If you still have waves you will need to mount a proper 3 prong connector and ground the Sigma Raijin metal case and PSU.

[Green beret]

@Green beret, Thank you for creating a new thread

Please do something with the size of the images!

I have experienced wavy lines because of ground-loops.

There are two kinds of ground in your arcade cabinet / super-gun: GROUND and 0V.

Your typical PSU will have 0V (COM / GND) and FG (FRAME Ground / Ground symbol)

The 0V should be wired on both sides of the JAMMA loom i.e. 1,2,A,B,27,28, e & f should all be 0V.

Your JAMMA connector is not populated correctly, you are missing 0V on 27,28, e & f

Check the correct pinout here:

http://www.jammaboards.com/jcenter_jamma_pinout.html

To avoid ground-loops I connect FG and 0V together on the PSU.

So this is what I would try first:

Connect two wires from the free GND tracks here: http://imageshack.com/i/idjONhaij to pin 27,28, e & f on your JAMMA connector.

Connect a wire on your PSU between FG and COM.

If you still have waves you will need to mount a proper 3 prong connector and ground the Sigma Raijin metal case and PSU.

Ok I bridged 27&28 together and added a wire to the ground of that side and e&f also together and a wire went to that side's ground. Then added a wire from COM to Ground on PSU.
Nothing, there were still waves.
So I wired a new power cable with a 3 prong connector. It passed through the hole of the 5 volts adjustment. (Now I have to open the Raijin if I want to adjust the 5 volts but until now I never touched and everything plays fine). Then I soldered it on the same points where the 2 prong cable was but without disconnecting the Japanese Jack or touch anything. The ground prong went on the Ground output of the PSU.
It is now fixed!! Everything is crystal clear in all M92s! I can't believe it! After so much time with the jail bars on screen!
Probably everything now will display crystal clear!
Thanks to all guys that proposed something but a SPECIAL THANKS goes to you! If it wasn't your detailed instructions I wouldn't have done it:)

[Green beret]

This case is now closed!

[rtw]

This case is now closed!

Glad to help , in closing proper ground is always a good thing!

There are actually PCBs out there which require 0V on both sides of the JAMMA so make sure all 0V pins are connected properly on the JAMMA connector.

edit: clarity

[Green beret]

This case is now closed!

Glad to help , in closing proper ground is always a good thing!

There are actually PCBs out there which require 0V on both sides of the JAMMA so make sure all 0V pins are connected properly on the JAMMA connector.

edit: clarity

I will post a pic of the Jamma connector when I go home for a last check
I hate jail bars in general because I used to have them on my Neo Geo AES 3.3 mobo version. After a long time of searching, maybe more than a year, I did the MKL's RGB bypass mod, removed all caps and resistors and Sony encoder from the video output. Pure RGB signal was guided then directly on scart where with pull down resistors 85ohm I managed to reduce its contrast in normal levels. Now there is an image quality I can't recommend enough!
BTW pull down resistors do the trick in the Raijin's scart too!

[rtw]

I will post a pic of the Jamma connector when I go home for a last check
I hate jail bars in general because I used to have them on my Neo Geo AES 3.3 mobo version. After a long time of searching, maybe more than a year, I did the MKL's RGB bypass mod, removed all caps and resistors and Sony encoder from the video output. Pure RGB signal was guided then directly on start where with pull down resistors 85ohm I managed to reduce its contrast in normal levels. Now there is an image quality I can't recommend enough!
BTW pull down resistors do the trick in the Raijin's scare too!

Please post a picture of your JAMMA conenctor and Sigma Raijin edge connector.

The 0V should be taken from pin 2 & 3 of the Sigma Raijin. The Sigma Raijin does not label the pins on the other side but if we use A,B,C you would pull 0V from: 2,3,B & C

http://i934.photobucket.com/albums/ad19 ... NUALP2.jpg

[Green beret]

I will post a pic of the Jamma connector when I go home for a last check
I hate jail bars in general because I used to have them on my Neo Geo AES 3.3 mobo version. After a long time of searching, maybe more than a year, I did the MKL's RGB bypass mod, removed all caps and resistors and Sony encoder from the video output. Pure RGB signal was guided then directly on start where with pull down resistors 85ohm I managed to reduce its contrast in normal levels. Now there is an image quality I can't recommend enough!
BTW pull down resistors do the trick in the Raijin's scare too!

Please post a picture of your JAMMA conenctor and Sigma Raijin edge connector.

The 0V should be taken from pin 2 & 3 of the Sigma Raijin. The Sigma Raijin does not label the pins on the other side but if we use A,B,C you would pull 0V from: 2,3,B & C

http://i934.photobucket.com/albums/ad19 ... NUALP2.jpg

This before the mod pic does not show anything?
https://imageshack.com/i/pdzxf0Ofj

[rtw]

This before the mod pic does not show anything?
https://imageshack.com/i/pdzxf0Ofj

It just shows that 0V is missing on pins 27,28, e & f.

Make sure to pull 0V from the Sigma Raijin edge connector from pins 2,3,B & C. (B is on the other side of 2, C on the other side of 3).

I don't have a proper drawing tool nearby so I can't illustrate what I mean

[Green beret]

This before the mod pic does not show anything?
https://imageshack.com/i/pdzxf0Ofj

It just shows that 0V is missing on pins 27,28, e & f.

Make sure to pull 0V from the Sigma Raijin edge connector from pins 2,3,B & C. (B is on the other side of 2, C on the other side of 3).

I don't have a proper drawing tool nearby so I can't illustrate what I mean

Ok I have to go home and take a pic. I should had taken pics last night though...
If they are missing it's just a little soldering?

[system11]

You should always have all grounds and all 5v pins populated on your looms.

It achieves two things - firstly it gives you more active contacts leading to better supply of power across the connector (in fact, the #1 cause of burned out edge connectors is people only connecting 1 +5v or GND pin because "hey they're all connected anyway").

Secondly some games actually don't have them all connected up together, I've seen inputs isolated before now, and some Sega boards actually separate one of the 5v pins from the other three too, if you don't have them all connected (some Japanese cabs don't) you end up with dead controls.

[Green beret]

You should always have all grounds and all 5v pins populated on your looms.

It achieves two things - firstly it gives you more active contacts leading to better supply of power across the connector (in fact, the #1 cause of burned out edge connectors is people only connecting 1 +5v or GND pin because "hey they're all connected anyway").

Secondly some games actually don't have them all connected up together, I've seen inputs isolated before now, and some Sega boards actually separate one of the 5v pins from the other three too, if you don't have them all connected (some Japanese cabs don't) you end up with dead controls.

My fingerboard is fully populated except 1 player 0 which I don't know what is it. On my Jamma connector I don't know exactly what is happening. I am a quick learner but I am still a rookie on this. I will post pics when go home and you guys tell me what you see.
I plan to buy a multimeter! Yes I don't have one yet. Where do I touch the positive and negative to see my voltage output if it is 5 volts?

[rtw]

My fingerboard is fully populated except 1 player 0 which I don't know what is it.

If this is your fingerboard:

http://imageshack.com/i/idjONhaij

You have not populated all the 0V (marked as GND in your picture) pins, ideally you should have 4, 0V wires going from your fingerboard to the JAMMA edge connector.

[Green beret]

My fingerboard is fully populated except 1 player 0 which I don't know what is it.

If this is your fingerboard:

http://imageshack.com/i/idjONhaij

You have not populated all the 0V (marked as GND in your picture) pins, ideally you should have 4, 0V wires going from your fingerboard to the JAMMA edge connector.

That picture was before I do the mod under your instructions. Now this it updated:
https://imageshack.com/i/pddxEQyZj
https://imageshack.com/i/f0fXhDClj

https://imageshack.com/i/f0jUDPQpj
https://imageshack.com/i/p8pHGDfyj
I put oversized pics for you to see easier and after a while I will remove image properties.
Thank you guys

[rtw]

I put oversized pics for you to see easier and after a while I will remove image properties.Thank you guys

It is correct now, enjoy the games

[Green beret]

I put oversized pics for you to see easier and after a while I will remove image properties.Thank you guys

It is correct now, enjoy the games

Great thank you again! You are great!
This is my set up and picture is with the ground activated!