Arcade Otaku - アーケード オタク

Why?

In my case, the flyback on my Hitachi GML chassis was going bad. Here is a video where you can hear the flyback buzzing and see artifacts on the picture:

https://www.youtube.com/watch?v=qIdz8hD2tUI"

The GML chassis is uncommon compared to the MS9, so it's harder to find parts for it, and I've never found a replacement flyback, so this is the next best thing. And lastly, the MS9-29 is just a better chassis.

How?

1) Create the adaptor for the 15 pin AMP-UP connector to the Impress.
You'll need the 15 pin AMP-UP mate:
http://www.digikey.com/product-search/e ... maction=on"
And two sizes of terminals:
2x http://www.digikey.com/product-detail/e ... ND/3045315"
7x http://www.digikey.com/product-detail/e ... ND/3488667"
And the AMP EI connector to adapt the Impress video connector:
http://www.digikey.com/product-detail/e ... ND/2309424"
Optionally some sort of momentary-on SPST switch for degauss.

The power cord to the Hitachi GML is just soldered in with no connector, so just clip it off near the chassis. It should be easy to see which wires are for what by the AMP-UP connector on the MS9-29 chassis, the only thing I would mention is that if you're going down the RGB line in order you'll notice the video GND and SYNC are swapped where the one on the outside goes inside, and you can't tell by the color of the wires. Crimp on your terminals and use the large ones for the power cable. The power cable has a thick shielding and to get it to fit I actually had to trim a bit off the top. For the AMP EI connector, solder to the base of the header and use heat shrink to keep it clean and separated. Here's a pic of my complete adaptor, without a degauss switch.
2) Modify the horizontal, degauss, and ground yoke connectors for the MS9-29 chassis.
You'll need some connectors:
https://greatplainselectronics.com/products.asp?cat=146"
2x part number LVP-02
2x part number LVP-01
4x part number 3751BS

It would be even cooler to find the header pins to adapt the existing yoke connectors, but I didn't bother finding the appropriate headers.

Look for the horizontal yoke connector, it will always be the red and blue wires, and replace the 3 pin housing with the 2 pin one. Replace the degauss connector with the same. Replace both grounds connectors coming from the tube with the single pin housing. One will go to the neck card and one will go to the chassis by the flyback.

3) Plug it in.

That is, the 15 pin AMP-UP, the video, the horizontal yoke, the vertical yoke, monitor degauss and 2 grounds, the neck card, and the anode cup.

Don't forget to plug in the remote board and put it in your control panel. Unfortunately, the MS9 remote board won't work in the same place as the Hitachi GML remote board. The center screw hole doesn't line up and even if it did, the pots don't line up with the holes in the plastic cover for the remote board.

Don't worry about the horizontal and vertical yoke connector polarity. If your picture is backwards in a direction, flip the connector.
Notes:

*) Any MS9-29 chassis should work. The letter suffix at the end of the model number like MS9-29T indicates which cab is was for, but they're all the same.
*) If your replacement MS9-29 chassis is missing the AMP-UP you'll have to wire straight to the video, power, and degauss in on the chassis, which I didn't do, so I don't know what parts you'll need. If you're looking for a replacement MS9-29 chassis I'd recommend making sure that is intact.
*) After I wired it up, it looked like my purity was off so I needed to degauss. I didn't wire up a switch so I just shorted it on the AMP-UP connector for a second.
*) I always order extra parts in case I screw up; they are dirt cheap.
Thanks to madgrab for his post here about this process: http://forum.arcadeotaku.com/viewtopic.php?f=4&t=22526"
Thanks to FrancoB for tips on connectors.

What do you think?

Awesome and very valuable thread

Do you see any picture related differences compared to the GML?

I don't really see any difference, but I haven't logged much time on it yet. The thing I was mildly surprised with is that it came up looking perfect right off the bat, with no adjustments. I had expected to adjust RGB cut off/gains because I thought the green gun in the Toshiba tube was weak, but I guess it wasn't.

Awesome thread, thanks!

Cool to see this documented and so glad to see your Impress is back. It is such a good feeling when you hit that switch and see a picture.
The MS-9 looks the same on mine as the GML, have some minor issues the bottom half of the screen. It almost looks krooked (maybe its convergence). But anything better than a dead candy and it never really bothers me. I got a second MS-9 on YAJ as a spare, and need to recap it and see how it compares.

I kinda went about a few things different but it is all the same. Did you remove the female part of the video header from the GML chassis and put in on the MS-9. The video connector you have showing didnt fit my MS-9 chassis.

I never got around to wiring the degauss button. I think all you need to do is wire it to power and add a switch.

Thanks for documenting this better than I did. I should have just taken the time to write everything down.

Congrats!

madgrab wrote:Did you remove the female part of the video header from the GML chassis and put in on the MS-9. The video connector you have showing didnt fit my MS-9 chassis.

I never got around to wiring the degauss button. I think all you need to do is wire it to power and add a switch.

No I created that adapter that connects the video out on the impress to the 15pin amp up. I know you didn't have the amp up connector so that made your project more complicated.

The degauss switch doesn't need power, just wire it to the 2 red degauss leads going to the amp up. Or if you don't have the amp up, I think it is pins 1 and 3 on the 5 pin header next to the 2 pin degauss header (from memory).

Ok so the AC power from your Chassis is fed through the 15 Pin AMP UP right?

I didn't quite understand your process but I see the adapter you used for video inputs now.

Is there any advantage to using the AMP Up?

Also did you ground the remote board for the chassis?

Yes the power goes through the amp up. The advantage is that it's simpler to go through that, no technical reason.

I didn't ground the remote board, but none of my games remote boards are specially grounded, including an egret ii with the same monitor/remote board.

I must resume this post due to exsactly map the male rgb connector on hitachi GMK chassis.


Basically on Hitachi chassis I have in order: 1)red ,2) green, 3)Blue, 4)Black , 5)White


On the capcom impress manual the last two colours are inverted!: red, green, Blue, White (H/V sync), Black (GND)


Anyone you remember what's the right combination ?

mukurop wrote: ↑December 19th, 2018, 11:13 pmOn the capcom impress manual the lat two colours are inverted!: red, green, Blue, White (H/V sync), Black (GND)

No they're not.


Black (video ground) goes to pin 4
Sync (white) goes to pin 5

I see

I got the adapter and swapped the hitachi chassis with a nanao Ms9, now I getting some geometry issue, basically there is a compression at center of the screen. Is there any pot on ms9 to solve this issue? On ms9 there is a narrow wide jumper but changing this did nothing.

You mean it's pinched in at the center of the screen? There's nothing you can do that apart from maybe trying to realign the yoke or swapping a component on the chassis.

It doesn't look that bad, possible unnoticeable in game.

You are 100% correct, ms9 chassis is the best for all settings options pots also have a flyback wich is a panzer, but since the hitachi is on par in 15kz picture quality but not have H. Linearitty issue on this tube /yoke then I will stay on hitachi.

When the picture is more compressed at the sides than in the middle or vice versa it's due to an incorrect capacity in series with the horizontal yoke. The phenomenon is called S-correction and shouldn't be confused with linearity which is asymmetrical. On the MS9 the capacitor should be C507 0.68uF 400V. In this case a lower value would need to be tried. But I wouldn't bother as it's barely noticeable. I could understand if it was something like this:

Thank you. I did this swap about 7 years ago and noticed this as well. I will give it a shot when I rescue my cab from storage.