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Joe

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Hi - hoping some technical wizard can magic up som help. I got a New Net City cabinet recently and have installed the RiverService JAMMA loom, however when i turned it on for the first time today i got a horrible image on the monitor - wrong colours, over exposed, blurred etc.

I read somewhere about the Toshiba monitor having two video inputs - one 0.7v and one 3v. My Dsub15 cable comes off the Jamma loom and goes to the VGA connector wired to the 0.7v monitor input (C in the image).

Is the answer to swap the plugs so the cable goes to the 3v (D in the image) ? I read on Neo Arcadia website someone did this, but it was a French translation so cannot guarantee its the same issue.

Before i try - and blow up the monitor /me, does anyone know or could shed some light on why the image is bad. I have rechecked all instructions ln the RiverService wiring and fairly sure the rest is hooked up correctly.

Thanks
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1. Does the monitor work correctly with 31k signals via the VGA plug? As it looks like you are missing some colors as well
2. Does the RS loom have any components inline with the video signal?

I have made my own harness and added 220ohm resistors inline for the RGB lines and worked perfectly connected directly to the VGA plug, nothing to swap on the chassis and still able to play JVS / 31k games :)
 
That certainly looks like the voltage levels are too high.

I would try the other connector.
 
1. Does the monitor work correctly with 31k signals via the VGA plug? As it looks like you are missing some colors as well
2. Does the RS loom have any components inline with the video signal?

I have made my own harness and added 220ohm resistors inline for the RGB lines and worked perfectly connected directly to the VGA plug, nothing to swap on the chassis and still able to play JVS / 31k games :)
Hi Pascal /Nem - my two dependable tutors. I feel i am always taking and not giving. After coronavirus is done you should come to Japan for beer! :)

I am ashamed to say i don't have any 31k inputs, only JAMMA boards, but the RS loom just has direct wiring to a dsub15 cable, nothing else in the line.

Since posting i found there is a NNC appreciation thread that alludes to these different inputs and consensus seems to be JAMMA in the 3v. I am going to try swapping tomorrow ... If you don't hear from me again i am probably fried somewhere in which case there might be a NNC cab up for sale by my wife.
 
Cool, good luck man :P

i know the chassis has 2 different inputs, but I only used the default one with me own loom with the resistors in line as I play JVS stuff as well on it :)
 
I have over a dozen of Toshiba PFs and not once have I ever run anything else except 31khz on them. So yeah, I have no first hand knowledge. However, I too remember reading of two inputs for different voltages, so that's what I would definitely try.
 
Partial success... Switched and picture is normal. However, it looks really dull and something strange in the bottom left (red coloring). The convergence looks very wrong (red and green either side of images)

Any ideas - is it advisable to mess with the rings at the back of the monitor to fix?

Would bad convergence account for a dull picture (despite brightness being turned all the way up?) tbe photos actually look better than it does in person.

Or have i just bought a lemon? :(

Thanks again guys
 

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Try a degauss via the monitors menu, see if the colors in the corners go away, the rest should be fixable with some adjustments.

I have not messed with the rings myself, so I would not start there, only as a last resort and if you know what you are doing ;)
Actually these monitors can be adjusted mostly via the OSD and there is also an ‘extended’ remote to give you a few more options over the stock.
 
Thanks Pascal... I've got into the extended menu and tried tinkering, but to no avail. I might email local arcade providers to see if they have engineers. The trials and tribulations of owning retro equipment! :)
 
That's dynamic convergence that you want to fix. Basically involves putting strips of magnetically permeable metal underneath the yoke to realign the electron beams shooting out of the neck of the monitor.

What do you mean dull? Not as bright? The colors don't pop out? Brightness, contrast, cut offs & gains should fix that.
 
That's dynamic convergence that you want to fix. Basically involves putting strips of magnetically permeable metal underneath the yoke to realign the electron beams shooting out of the neck of the monitor.

What do you mean dull? Not as bright? The colors don't pop out? Brightness, contrast, cut offs & gains should fix that.
Hi Nem/Pascal

When i say dull, it is more that the whites don't seem bright and the picture does not pop. The whole picture is muted. If i compare to other arcade monitors. I have played around with the gain, cut off, brightness and contrast, and convergence rings, even purity ring, and got it as good as i can. I have attached a picture, it looks brighter in the picture than in real life ironically.

Only thing i have not touched High Voltage Adjustment pot on the back of the monitor... Seems risky.

Two thoughts/questions come to mind:
(1) i swapped the cables on the monitor input so the d-sub 15 goes to the 3v input rather than the 0.7v input. Is 3v still okay for raw JAMMA input? If not, maybe this could have something to do with it, although the picture does not seem over saturated.

(2) The only other thing i can think of is maybe using the Retro Scaler A1 from Invizim to bring the JAMMA rgb down to VGA levels then use the 0.7v input (this would upscale 15hz to 31hz) and line double. Not sure if this would result in a better image or not (would i lose scanlines too etc?)

As an aside, i hooked up the audio using the line converter, following your advice. Audio is beautiful! Thanks!

Thanks
 

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I’m not a pro when it comes to monitors, but I would start with checking/adjusting the B+ and verify it is correct.

not sure if the 2 different input connections would require different calibrations or not?
 
15khz and 31khz definitely have a different set of saved settings on the PF.

I wouldn't touch B+, but I would turn the screen pot on the flyback. Go in to the test menu, put your brightness and contrast setting in the middle position (either 50 or 100, can't remember) and turn the screen pot clockwise. When the background turns grey you've gone over, turn slightly back. Then calibrate again.
 
Yes stuff like geometry, contrast and brightness definitely have 2 different settings for 15/31k.

I mean if I calibrate my monitors B+ etc on the 31k input would this be ok-ish for the second 15k input as well or require a check?
 
That's dynamic convergence that you want to fix. Basically involves putting strips of magnetically permeable metal underneath the yoke to realign the electron beams shooting out of the neck of the monitor.

What do you mean dull? Not as bright? The colors don't pop out? Brightness, contrast, cut offs & gains should fix that.
Hi Nem/Pascal
When i say dull, it is more that the whites don't seem bright and the picture does not pop. The whole picture is muted. If i compare to other arcade monitors. I have played around with the gain, cut off, brightness and contrast, and convergence rings, even purity ring, and got it as good as i can. I have attached a picture, it looks brighter in the picture than in real life ironically.

Only thing i have not touched High Voltage Adjustment pot on the back of the monitor... Seems risky.

Two thoughts/questions come to mind:
(1) i swapped the cables on the monitor input so the d-sub 15 goes to the 3v input rather than the 0.7v input. Is 3v still okay for raw JAMMA input? If not, maybe this could have something to do with it, although the picture does not seem over saturated.

(2) The only other thing i can think of is maybe using the Retro Scaler A1 from Invizim to bring the JAMMA rgb down to VGA levels then use the 0.7v input (this would upscale 15hz to 31hz) and line double. Not sure if this would result in a better image or not (would i lose scanlines too etc?)

As an aside, i hooked up the audio using the line converter, following your advice. Audio is beautiful! Thanks!

Thanks
The tri-sync helper would do what you need - no need to upscale as you already have 15kHz. @BuddyC has first hand experience with same monitor :).

https://irkenlabs.com/jammafier/tri-sync-helper
 
Wow i had no idea my NNC monitor had two different inputs expecting different voltages.

My jamma harness and the VGA cable appear to both be connected to the same input on mine, as the colour/saturation etc is identical across both inputs. (I dont notice any over exposure or anything using scalers such as retroscalerA1 either).

Luckily I have not had any problems with my Toshiba 29 (except the whole image could to with a 2degree rotation to the right) which has meant I have never had to peek at the back or try to adjust anything except by using the regular button panel (and added 2 buttons for extra menus).
 
That's dynamic convergence that you want to fix. Basically involves putting strips of magnetically permeable metal underneath the yoke to realign the electron beams shooting out of the neck of the monitor.

What do you mean dull? Not as bright? The colors don't pop out? Brightness, contrast, cut offs & gains should fix that.
Hi Nem/PascalWhen i say dull, it is more that the whites don't seem bright and the picture does not pop. The whole picture is muted. If i compare to other arcade monitors. I have played around with the gain, cut off, brightness and contrast, and convergence rings, even purity ring, and got it as good as i can. I have attached a picture, it looks brighter in the picture than in real life ironically.

Only thing i have not touched High Voltage Adjustment pot on the back of the monitor... Seems risky.

Two thoughts/questions come to mind:
(1) i swapped the cables on the monitor input so the d-sub 15 goes to the 3v input rather than the 0.7v input. Is 3v still okay for raw JAMMA input? If not, maybe this could have something to do with it, although the picture does not seem over saturated.

(2) The only other thing i can think of is maybe using the Retro Scaler A1 from Invizim to bring the JAMMA rgb down to VGA levels then use the 0.7v input (this would upscale 15hz to 31hz) and line double. Not sure if this would result in a better image or not (would i lose scanlines too etc?)

As an aside, i hooked up the audio using the line converter, following your advice. Audio is beautiful! Thanks!

Thanks
The tri-sync helper would do what you need - no need to upscale as you already have 15kHz. @BuddyC has first hand experience with same monitor :).
https://irkenlabs.com/jammafier/tri-sync-helper
Thanks Invizm - that sounds the ideal solution! Your store appears out of stock of these. Any idea when they will be back in stock? Can i put in a preorder?

Thanks
 
Wow i had no idea my NNC monitor had two different inputs expecting different voltages.

My jamma harness and the VGA cable appear to both be connected to the same input on mine, as the colour/saturation etc is identical across both inputs. (I dont notice any over exposure or anything using scalers such as retroscalerA1 either).

Luckily I have not had any problems with my Toshiba 29 (except the whole image could to with a 2degree rotation to the right) which has meant I have never had to peek at the back or try to adjust anything except by using the regular button panel (and added 2 buttons for extra menus).
Great thing about these forums, the things people find out inadvertently. My learning curve has been huge. Wish there was a tuition course on this stuff when i was growing up - i would not have wasted my time on my normal school subjects :)

It's strange two cabinets the same act in different ways. Do you have any attenuation on your jamma harness at all that allows it to look okay through the VGA 0.7v input?

Thanks
 
The tri-sync helper would do what you need - no need to upscale as you already have 15kHz. @BuddyC has first hand experience with same monitor :).
https://irkenlabs.com/jammafier/tri-sync-helper


Yup! The tri-sync helper works like a treat!
Any ETA for the tri-sync helper and new jammafier @invzim?
And yeah. There are different settings for 15k and 31k. Great since I needed to boost some of the colors in 15KHz and not in 31KHz. Awesome monitor for calibration junkies!
 
The tri-sync helper would do what you need - no need to upscale as you already have 15kHz. @BuddyC has first hand experience with same monitor :).
https://irkenlabs.com/jammafier/tri-sync-helper


Yup! The tri-sync helper works like a treat!
Any ETA for the tri-sync helper and new jammafier @invzim?
And yeah. There are different settings for 15k and 31k. Great since I needed to boost some of the colors in 15KHz and not in 31KHz. Awesome monitor for calibration junkies!
Thanks Buddy. Did you try swapping the connections like i have (VGA to 3v input on monitor) before trying the tri-sync helper. If so, was there an improvement in quality when you moved it back to the VGA 0.7v input?

Thanks
 
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