Monitor blank screen

Shinydaz

Shinydaz

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Hi folks, I brought a sega naomi, it's had all its hardware ripped out but still had the monitor and wiring. Now I plan to put a pc in it and run some emulators. My first problem was no transformer, I got one of those at giz10p.Co.uk as Craig only lives 30 mins away. Came home a bit excited and connected it up. Now should it display any test screen when nothing is connect to it? It clicks into life but no picture? I've connected up a pc with correct resolutions and still nothing, I kind of knew this wasn't going to be easy :( all I wanna do is play some games !! It's the sanwa 29e31 monitor, it's a virtua soccer 4 cab, not that old. Thanks for incoming advice :)
 
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ZedEx48K

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silverfox0786 said:
a Naomi without a cart should display the Naomi logo and Error 1 for no cart

make sure your dips are set to VGA 31K and not 15K Jamma
Click to expand...

As he says though he's had a PC connected up too.

Check for neck glow*, check voltages, deff in 640x480 60hz on pc? Otherwise could be a dead chassis.

*also make the room completely dark, you should see the screen has a minor amount of illumination from being turned on.
ZedEx48K2015-07-23 16:23:25
 
Shinydaz

Shinydaz

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I have no naomi in it, it's a bear shell with just wires, I'm a noob when it comes to this, I was hoping to plug and play with screen res at 640 x 480 60htz, its Deffo getting power, should it display anything when not connected up? Test screen etc...? I can hear the demag button is working and monitor clicks on but not a thing on the screen.
 
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obcd

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It shouldn't display anything when no video signal is connected. (It's not like the last generation pc monitors that display "no signal" or show a blue screen when no signal is connected.)

Pc monitors have an eeprom that contains the available resolutions the monitor can display. The Sanwa isn't having this. Are you sure you are feeding the monitor with 100 - 110V AC?

You could try to turn up the screen voltage a little (it's normally the bottom potmeter of the lopt). The display background should become gray instead of black if the monitor chassis is working as expected. If you connect the screen to a laptop, make sure it's outputting video on it's connector. On some laptops, you need to manually switch between it's own screen and the external vga connector.
 
Shinydaz

Shinydaz

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It has got an original naomi transformer on it, so I presume it's getting 110v. I was told I can test it with an xbox 360 with vga cable, pity I threw my vga cable out a year ago. It's a desktop pc I'm connecting.
 
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ZedEx48K

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Ok, the laptop even with the wrong resolution/refresh rate should still give you an image, thought it will be all kinds of rolling and doubled up, to make sure you are outputting to the external VGA you would need to hook it up and press winkey+P together (Win 7, 8 & 10) to get the output menu up, set it to duplicate, if that fails inc no duff image then I would think it's the chassis if you were sold a working PSU and all cables are hooked up accordingly (pink and blue if I remember correctly), you mention a click, I remember I had a dead chassis and part of it would click on power, and that's all it did.
 
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obcd

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Was it sold with a "working monitor chassis" or was it sold "untested"?

(In 95% of the cases this means tested and not working)
 
Shinydaz

Shinydaz

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It was sold as Virtua striker shell, I was living in hope the monitor would at least work, maybe this is why it was stripped of all its good bits?
 
Shinydaz

Shinydaz

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Quick update, monitor now showing a line in the centre rising to the middle.
IMG_20150725_19797.jpg


I then connect it to my pc set up at 640 x 480 at 60hz and the line grows to the top and moves around.
IMG_20150725_44783.jpg


Tell me the bad news :(
 
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obcd

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Just Curious, what have you done to get this far?

Around the neck of the picture tube is the deflection coil. It contains one coil to move the beam from top to bottom (the vertical coil) and one coil to move it from left to right (the horizontal coil)

The picture you are seeing is what happens if the horizontal coil isn't energised. The whole picture collapses to one vertical line in the middle of the picture tube.

Maybe the connector soldering for that coil broke, or a wire broke off from the deflection coil itself.

Since you see something on your tube, the horizontal stage and LOPT transformer are working. It's that same circuit that energises the horizontal deflection coil as well. That's why I am thinking in the direction of a broken wire or soldering. To my knowledge, those chassis have a separate connector for the horizontal and vertical coil. (Some other brands combine both coils into one connector)
 
Shinydaz

Shinydaz

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Like I said, I got it as a shell with no details if it works or not, I transported it to my house. Fitted a transformer, hooked a pc up to it at 640 x 480, no picture or nothing, just monitor clicking a couple of times when it was switched on and off. Then I tried it again a couple of days later and it came up with these lines.
 
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obcd

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good point. Normally it's mounted under the tube and accessible if you open the compartment with the controls (the joysticks and the buttons that control the games) It might be under that plastic folie that is hanging there.
 
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