Portable TV RGB!

Started by Segasonicfan, August 21, 2004, 09:24:36 PM

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Segasonicfan

Well, after an extensive amount of searching, I think I have found how to input RGB signals into a portable Casio EV-660 Television.  This TV has an IR3Y1BA Casio Chroma 46-pin IC chip inside that converts the the S-video, Composite, and RGB signals.  Take a look at the schematic here:  

http://chemisette.free.fr/Casio-QV700.pdf

See the S-In, R-in, B-in, Gin?  Wouldn't that work for Sync, red,blue, and green to display on the TV?  I tried the mod but was quite unsuccessful as this chip is one pain in the ass to solder to.  However, I did get an ungrounded picture for a brief moment through my trials, so I believe this may work :)  Anyone think it shouldn't?  

-Segasonicfan
MY WEBSITE: https://segasonicfan.wixsite.com/retro
I design PCBs for retro game systems :)

NFG

If the TV doesn't already support RGB you may not be able to switch from one video input to another, you might try connecting your RGB lines to the RGB OUTPUT of that chip and see what you get.

Good bit of research digging up that schematic, finding info on obscure chips is f**king tough work, most of the time you end up with the same dozen chinese/russian sites trying to sell access to their PDF lists, no actual details.  And trying to search the manufacturer's site is usually next to impossible as well.  

atom

Yes, I have learned that it is a pain as well.

What lawrence is saying is you should try to bypass the chip and go right for sending your signal to the guns. If the IC supports rgb, it doesnt mean the tv will use that part of the chip.

Keep us updated on how the mod progresses.
forgive my broked english, for I am an AMERICAN

Segasonicfan

Well, I tried the direct RGB lines, but unfortunately I had screwed up the other pins too much.  I'm getting another one soon, and I will let you know how that goes.  Would the RGB inputs have voltage outputting from them?  I thought that was weird (and I don't want to ruin my CDX RGB lines, so I'm going to finish testing it all using a model 2).  Thanks for the advice.

-Segasonicfan
MY WEBSITE: https://segasonicfan.wixsite.com/retro
I design PCBs for retro game systems :)

Segasonicfan

well, that TV broke but i did finally figure out how to solder to those tiny pins.  I have another 5" portable tv, an rca 16-3066.  It has a Sharp IR3Y31M IC chip inside.  I found the pinout here:

http://www.lcdvision.com/download/interface_ic/IR3Y31M.pdf

I tried hooking it up to the RGB lines like suggested, and all I got was a vague partial moving picture.  it looked terrible.  All my wiring was 100% correct though, i checked it over and over (and its obvious where the RGB traces run-to 3 capacitors on the board, I soldered to them.  And I soldered to the sync out and ground as well.  Now I'm going to try soldering to the EXT RGB lines.  I take it that stands for external RGB lines, and hopefully that will allow me to connect the Genesis 2 (I'm using its RGB lines to save my CDX any possible damage.)  I can't find an EXT Sync, so I'm not sure what to do about that.  Take a look at the schematic and let me know what you guys think!

-Segasonicfan
MY WEBSITE: https://segasonicfan.wixsite.com/retro
I design PCBs for retro game systems :)

Richter X

Slightly OT question here: If I found a decent Flatscreen TV (Not HDTV) with component inputs, how hard would it be to modify it to accept an RGB signal through the component input jacks?

Segasonicfan

VERY.  Im doing this stuff with protable TVs and its still hard as hell (with much less chips to identify).  I say don't even try it.  

I'm still having no luck with the RGB signal.  I tried the RGB and Sync Out lines again and no luck :(  Genesis 2 does RGB right?  And I don't combine the Sync+comp video...right?

-Segasonicfan
MY WEBSITE: https://segasonicfan.wixsite.com/retro
I design PCBs for retro game systems :)

Aidan

#7
The RGB out connections on the chip you were looking at are highly processed, gamma corrected, contrast corrected and lots-of-other-things-corrected. Driving them directly also involves overcoming the amplifiers inside the chip, which might explain why you're getting a poor picture.

The EXT RGB lines are designed to allow the input of an RGB signal. Check that these are not connected to something else first. You then have to tell the chip that it should be accepting an RGB signal instead of the normal signal. That's the purpose of pin 7, which looks like it's labeled "SW". When it's connected to ground, the chip will process composite/S-video signals. When it's connected to VCC, it'll process the EXT RGB lines. That suggests that you'll have to disconnect this pin from ground, and connect it to VCC1 (pin 43?). Be aware that the chip has TWO power supplies, VCC1 and VCC2, which may be at different voltages!

It also looks like there's a Sync Input, which affects how the chip processes signals. At a guess, you'd need to hook your sync up to the sync input which is pin 36. Ensure you've disconnected any other circuitry connected to that pin first! However, there is an alternative, pin 38 (Sync Sep) might be worth trying, but it will probably have pin 2 connected to it. In that case, you'd need to disconnect any other circuitry from pin 38, and try injecting your sync signal in there.
[ Not an authoritive source of information. ]

Guest

QuoteSlightly OT question here: If I found a decent Flatscreen TV (Not HDTV) with component inputs, how hard would it be to modify it to accept an RGB signal through the component input jacks?
The TV itself would most probably convert the component signal to RGB so you could connect the input jacks to the output of that convertor. It really depends on the model.

wxj

QuoteWell, after an extensive amount of searching, I think I have found how to input RGB signals into a portable Casio EV-660 Television.  This TV has an IR3Y1BA Casio Chroma 46-pin IC chip inside that converts the the S-video, Composite, and RGB signals.  Take a look at the schematic here:  

http://chemisette.free.fr/Casio-QV700.pdf

See the S-In, R-in, B-in, Gin?  Wouldn't that work for Sync, red,blue, and green to display on the TV?  I tried the mod but was quite unsuccessful as this chip is one pain in the ass to solder to.  However, I did get an ungrounded picture for a brief moment through my trials, so I believe this may work :)  Anyone think it shouldn't?  

-Segasonicfan
jj

Darklegion

The main Rin, Gin etc lines are usually for OSD.However IIRC, even if they are being used for OSD you can often just input them directly and you will just get black colours for the OSD when using RGB :) Alternatively you can cut the tracks leading the OSD chip (which is usually integrated with a chip that does various functiopns) and solder in a switch, or just leave it if you don't need it.
As for sync, be careful with it.I blew a chip by inputting composite sync into what I thought was a composite sync input.Thankfully said chip was actually still available to buy, so all was good once I replaced it.

Just had a look at the sharp schematic, you'll need to supply VCC to pin 7 for to enable the EXT-RGB inputs.Also you might want to use a DC coupled RGB source (such as a PS1/PS2 cable without the 220 uf capacitors) as there is a AC coupling circuit in there already, and although I am not sure if it will affect anything in this case it is worth trying in case you have problems.



grahf

Just a note: the hipgear screenpad uses this control chip. I tried (unsuccesfully) to drive it with rgb from a pc engine. I studied the datasheet to the best of my ability, but no luck. I did connect the input switch at pin 7 correctly also.
Its possible that its a sync problem, but i decided to leave it be for the time being since i dont really know what im doing yet :D Its hard to solder to those pins anyhow, even with a scope.