TV RGB mod thread

[Housematt]

Hi evryone, Long time lurker (like 20 years), first time poster.

I've successfully RGB modded my Sony KV-G21S11 - Looks absolutely amazing!
Thanks to all the folks that have posted in this thread, I have been silently copying your work
this was also called KV-G21M1, KV-G21P1, KV-G21S1 when sold in other geographies. Its a BG-1S chassis and the jungle is TDA8375

This is about the easiest RGB mod I could hope for.
The S1 chassis has a "teletext" (closed captioning) card in one of the headers, that card header already has RGB and BLK pins, the pins go to an active input on thie jungle, and they already have resistors tied to GND and capicators to tame the signal to what the Jungle expects.
My question is about the BLK voltage;
0-1v = composite
1v - 4v (approx) = RGB (thisi s what i want)
5v+ = blanks everything, no picture
At the moment i've taken 9v off a line on the A board, wired up 3 x LED's in series, this drops the 9v down to approx 3 volts. That works well for BLK

So question is - is there a better way to get approx 3v off this chassis (S1) for BLK without having to wire a whole bunch of LEDs up in series mickey-mouse style.
Or alternatively - other than looking silly is there anything WRONG with having these three LED's in series?

Any thoughts would appreciated.

[qjkxbmwvz]

So question is - is there a better way to get approx 3v off this chassis (S1) for BLK without having to wire a whole bunch of LEDs up in series mickey-mouse style.

If those LEDs are red, green, and blue, and if they come on only when you're using RGB, then I can think of no better solution: you've already achieved perfection. Otherwise, you could get 9V down to 3 by using resistors. Just get three of the same one and put two in series running from 9V to where you want 3 and, from there, run the third resistor to ground.

[Osirus]

So question is - is there a better way to get approx 3v off this chassis (S1) for BLK without having to wire a whole bunch of LEDs up in series mickey-mouse style.

Voltage divider: https://ohmslawcalculator.com/voltage-d ... calculator

I've done a couple mods using a 2.2k ohm resistor as "R1" and a 1k as "R2" to bring the 9V rail down to around 3V for blanking.

[MarkOZLAD]

So question is - is there a better way to get approx 3v off this chassis (S1) for BLK without having to wire a whole bunch of LEDs up in series mickey-mouse style.

Voltage divider: https://ohmslawcalculator.com/voltage-d ... calculator

I've done a couple mods using a 2.2k ohm resistor as "R1" and a 1k as "R2" to bring the 9V rail down to around 3V for blanking.

The set will already have an "R2" resistor in place on the blanking line, R330. If you add a resistor of the same value as r330 to your 5V line you'll halve the voltage going to the blanking pin, voila 2.5V.

Can test this by testing the resistance to ground on Pin 4 of CN106.

The diode idea is a classic!

[qjkxbmwvz]

I'm on the lookout for TVs to mod, my last two having been too new for it. I've filtered things down to sets that I think might be moddable.

There's a nearby TV going for $5: a JVC AV-2050, manufactured in 1991. I can't find a service manual for it, and my instinct is that it's rather old. (My Amiga 1080, a 1985 unit, recently died on me. Can't tell what's wrong with it - recapping hasn't helped - but I wasn't quite happy with its geometry: it had some uncorrectable barrel distortion.)

There's also a Trinitron KV-35S36, manufactured in 1999, going for $30 - and another of the same, but from 1997, going for free. The free one I think has been left outside for the last eleven days. Either one of those Trinitrons would be hard to get into my car - they weigh more than I do!

For $50, I could have a Zenith Space Command, but I'm sure that that's way too old.
For $80, I could have a Toshiba 27A43, but that price seems out of proportion.

[Osirus]

The KV-35S36 is an AA-2D chassis which has been done by several people in this thread, including me just a few replies back. But you're right a 35" Triniton is a minimum 2-man operation.

[Housematt]

So question is - is there a better way to get approx 3v off this chassis (S1) for BLK without having to wire a whole bunch of LEDs up in series mickey-mouse style.

If those LEDs are red, green, and blue, and if they come on only when you're using RGB, then I can think of no better solution: you've already achieved perfection.

THank you for your response, and for this brilliant idea - I was solving the wrong problem by trying to hide my LED shame. I shall embrace the RGB - loud and proud!

[maquese]

I've been working on an RGB mod for a Sony KV-27EXR20 (ANU-2 chassis), and so far it's gone well and been pretty easy (I'll post more info on the process soon to help others if they need it). I've run into one issue though. SNES and NES games look great, though I have to lower the contrast quite a bit to keep the picture from blooming a lot. I hooked up my model 1 genesis, and the picture is terrible. It's crisp, but the colors are muddy and dark. Using the 240p test suite, if I do the solid color tests, the colors aren't very vibrant, and the white is more of a pink-ish gray. The Pluge test looks like shades of brown rather than grayscale. Not sure if my SCART cable is just bad? It's the kind that generates it's own csync rather than using the composite from the Genesis. Suggestions?

Sorry for the lack of pictures, but it really doesn't come across well on the phone.

[qjkxbmwvz]

SNES and NES games look great, though I have to lower the contrast quite a bit to keep the picture from blooming a lot. I hooked up my model 1 genesis, and the picture is terrible. It's crisp, but the colors are muddy and dark. Using the 240p test suite, if I do the solid color tests, the colors aren't very vibrant, and the white is more of a pink-ish gray. The Pluge test looks like shades of brown rather than grayscale.

Does it do these things on the stock inputs?

[maquese]

SNES and NES games look great, though I have to lower the contrast quite a bit to keep the picture from blooming a lot. I hooked up my model 1 genesis, and the picture is terrible. It's crisp, but the colors are muddy and dark. Using the 240p test suite, if I do the solid color tests, the colors aren't very vibrant, and the white is more of a pink-ish gray. The Pluge test looks like shades of brown rather than grayscale.

Does it do these things on the stock inputs?

Using the garbage composite cable I made to practice soldering the picture looks fine other than being a meh composite signal. I'm still in the testing phase so I don't have a connector wired up to the tv, just wires coming out the back that I'm attaching to the SCART cable with alligator clips. If I remove and replace the ground, the picture goes extremely bright and then slowly fades to the muddy, crap colors. So maybe I've got a crap ground in the cable?

[djanice1980]

The 75 ohm resistors need to have legs twisted like 8 bit guy part 1 and the RGB injected between them.

I did as you said and it worked perfectly!!! Thank you for your help.


Here are some pics.

https://imgur.com/gallery/SpGeCDK

[qjkxbmwvz]

Success!

I got a KV-35S36 and got it doing RGB fairly easily, albeit with a bit more difficulty than the model that Osirus posted about would've posed. Now I just need to mount the SCART connector (on the right side I've decided). After that, I'll add a headphone connector and maybe a component input. Pics when it's all done!

[Osirus]

Success!

I got a KV-35S36 and got it doing RGB fairly easily, albeit with a bit more difficulty than the model that Osirus posted about would've posed. Now I just need to mount the SCART connector (on the right side I've decided). After that, I'll add a headphone connector and maybe a component input. Pics when it's all done!

Yours looks like it doesn't have those handy CN1801 and CN1802 pads on it.

I'm thinking about opening mine back up and redoing the mod for RGBHV instead of RGBS. I'd be integrating this circuit internally: https://www.retrorgb.com/building-a-pas ... biner.html

[maquese]

Well, I'm at a loss for what to try. Hooked up a few more systems, and my results aren't too good.

Here's the service manual: https://elektrotanya.com/sony_anu2_chas ... nload.html

For the mod I did the following:
1. Added a 150R between R319 and ground to drop the 5v from the consoles to the 3v that the tv wants.
2. Wired the 5v, ground, and RGB wires to header A-31 (pins 15-18 on the JC)
3. Wired a line from the Video 1 composite to use for sync
4. Wired the 5v, ground, RGB, and composite sync wires to a scart connector.

Connecting the NES or SNES, I get a great picture:


Connecting the model 1 Genesis, I get this:

(sharp picture, but very muddy, dark, and brownish)
* I also tried another RGB cable I have with the genesis and I get no RGB output at all *shrug*

Connecting the playstation, I get this:

(Same as the genesis, sharp picture, but very dim and muddy colors)

Finally, the really odd one, the Saturn:

When I first connected the Saturn, the picture was perfect, like the NES/SNES. I played the game for about an hour, and then noticed that the colors were getting dim. Since then, every time I connect the Saturn to the tv, it looks like the picture above...

Before I wired the scart connector, I was just using alligator clips between the scart from the consoles and the tv wires. If I removed the ground wire and than reconnected it, the Genesis would work for about a minute before going back to the crap colors and dim picture.

Any suggestions?

[MarkOZLAD]

maquese

As an experiment can you try increasing the screen voltage on the TV when you have the dimmer consoles in?

[matt]

Well, I'm at a loss for what to try. Hooked up a few more systems, and my results aren't too good.

Here's the service manual: https://elektrotanya.com/sony_anu2_chas ... nload.html

For the mod I did the following:
1. Added a 150R between R319 and ground to drop the 5v from the consoles to the 3v that the tv wants.
2. Wired the 5v, ground, and RGB wires to header A-31 (pins 15-18 on the JC)
3. Wired a line from the Video 1 composite to use for sync
4. Wired the 5v, ground, RGB, and composite sync wires to a scart connector.

What are you using for sync from all of those consoles? I've done a couple of Sony mods and noticed that the type of sync used affects the brightness of the picture.

[maquese]

I tried to fiddle with the voltage to the tube as MarkOZLAD suggested, but honestly, I couldn't figure out how to do it and wasn't super comfortable just poking around inside. I got to thinking about an older post where someone mentioned that the pip board that's missing from this model had some caps on the output lines. Looking through the schematic, turns out they're 1uf, so I added a cap to each of the RGB lines, and viola, perfect picture.

(Hard to get a clean shot with the phone sometimes)
Saturn


Genesis


I didn't get a picture of the Playstation, but the picture is just as good as the others now using composite sync. The NES/SNES still look great as before.

So now about all I have left is to install the connector into the back of the case and wire up the audio from the SCART connector. All in all, I'm pretty happy with the results. The tv doesn't have the best convergence/linearity, and the picture seems to be slightly tilted to one side, but it's all stuff I can either live with or deal with later.

Thanks again to everyone on this forum for helping, even if indirectly

[skum]

...so I added a cap to each of the RGB lines, and viola, perfect picture.

Just to be sure, you did not have in-line caps on each line? RGB was going straight into the jungle?

[maquese]

...so I added a cap to each of the RGB lines, and viola, perfect picture.

Just to be sure, you did not have in-line caps on each line? RGB was going straight into the jungle?

Correct. In the original pictures with the bad output, the RGB lines from the SCART cable went straight to an unpopulated header on the tv board that would have been used for Picture-in-Picture. That header connected to the jungle through 100 Ohm resistors on each line.


Based on a previous post and looking at the schematic for the PiP board, I added 1uf caps to each input line (leaving the existing resistors), and that fixed the issues.

[vol.2]

Hello all. I really need some help from the experts on my RGB mod. I'm doing an older set, and the text inputs on the Jungle IC have some confusing inputs that I'm having trouble sorting out.



I'm trying to mod this little Toshiba guy:



This is the Jungle IC, it's conveniently on this daughter board, but I have to remove/resolder it each time I make an attempt:



I tried both the TV and the Text inputs. Syntax recommended the TV inputs, but I zero luck with those so far. The text inputs I seem to at least get something that is garbled.

I can't figure out exactly what to feed what. The RTX,BTX,GTX seems obviously the RGB, but then it wants

6-Pedestal Clamp
12-TV/TX select signal

I'm not sure how it derives sync from any of this, I was suspecting that it is using the Luma from the main signal to do that, but not sure.

Here's the Jungle chip flow chart and the waveforms "explaining" the other inputs. I think that blanking blanks the text and not the video image. I think the TV/TX input might be what we are thinking of as blanking.

Flow chart:



Waveforms:




I think tonight I'm going to try and suck the pedestal clamp from the main video IC, which says it exists on pin 14. It's also feeding some other crap, so I think I'll put that noise on a diode. Hopefully it won't rectify out anything important. I guess I'll try to use luma to feed the TV/TX input? Or maybe pedestal clamp should be Luma and TV/TX should just go high like a blanking pin?

Please if anyone has a moment to check any of this out, I would be grateful.

Thanks

[vol.2]

So, no idea if anyone is following this at all, or wants an update, but here's where I am right now.

-I have the RTx, BTx, GTx inputs hooked up to my external RGB lines through a 0.1uf cap and tied to ground through a 75ohm resistor.

-I've got pin 12 (Tx/Tv select) tied high to ~3V (it's a little high, but it shouldn't hurt anything and 3V is good enough until I can build a voltage divider.

-I've got pin 6 (Pedestal Clamp) coming from the same Pedestal Clamp circuit that it was already tied to. It's a complicated DC restoration circuit, so I think I have to leave it. I disconnected the Char Gen chip from the Clamp pulse circuit to prevent it from interfering with things.

-I've got pin 9 (brightness) wired to a 5k pot tied between Vcc and ground on a voltage divider giving it the recommended (as per the datasheet) ~4-5VDC.

This is what I'm getting:

I can't seem to figure out a .gif embed here, so here's a link: https://i.imgur.com/8mF0sDz.mp4


So, what you are seeing is the picture coming on when I press the video button (because the TV defaults to RF input everytime you switch it on). It's too green, but I can solve that (there are Blue and Red level adjust pins).
The issue is that it's switching "off" the display because there is a built-in timer that turns off the display text normally. I thought I cut it out of the circuit when I disconnected the Char Gen chip, but I think it's tied to the Tuner IC chip in some way. I have one connection that I can think of, but I can't just strip the Vcc from the Tuner chip because it also handles the A.V switch and the remote.

I'm going to keep working on it, and I'm making some progress, but I still could use a hand if someone can look at this.

Thanks


Edit: isolating the tuner chip stopped the "turn-off" effect. Now I have to work on the colors. It's weird because the cut-off colors are no longer valid. When I put it in service mode, the line is all funky colors. No clue what that's about, but I clearly changed something fundamental.

[vol.2]

Ok. I got it working. More or less.

There's a couple of weird things I don't understand, and a couple of image issues. All in all, it looks better than it did with composite. My biggest concern is that I may have changed the way the set is running too much and made something liable to break, or to run the tube too hard. I think it ok because in theory it would be a similar brightness for a similar G2 level, but I don't know. I don't have a HV probe for my multimeter, but I'm going to get one to make sure it's still around the same thing.


I have to apologize, I don't have a great camera.

Spoiler

Here's the issues. There is a vertical tearing towards the top. Not sure about how to remedy or what the cause is.

Spoiler

Also, there is banding. I think maybe resistor or capacitor values can help with these things?

Spoiler

I'm really curious as to why the colors are all mixed up now. The way it's wired from the Playstation, Red goes to the Blue text input, Green goes to the Red text input, and Blue goes to the Green text input.

But it basically "works." Not sure how I feel about it, but it looks a hell of a lot better than composite did. There is no color fringing or bleeding like there used to be. Now even the red is pretty solid.


Edit: I figured out why the colors were all mixed up. I was looking at the Datasheet for the AN5352N, and the unit I have used a AN5352 with no N. Apparently the only difference is the ordering of the Text color inputs in order to make one color the "main" color for text output. CORRECTION: The datasheets are the same. Toshiba just decided to mix up the colors because they only needed 2 of them and I guess it must have been more convenient to route it that way on the PCB. Seems like they didn't expect anyone to hack it in 30 years.

I also discovered that the vertical banding was already there, but it's very light and impossible to notice when you are using the composite inputs at a normal brightness level. It only shows up when you *crank* the brightness. I'm not sure what the issue could be. It's not an electrolytic because they are all new. I think one of the big film caps may have drifted in value perhaps?

Also, the flyback transformer seems a little weak because you have to turn the focus almost all the way to get it to focus, and the little amount above that point brightens the screen. Seems like classic failure to me, so that might be it. I'm going to check the HV pretty soon once I pick up the meter. I got a pretty cheap one on fleabay.

If anyone has any ideas about the vertical banding (or the horizontal tearing) and how to remedy that, I would be all ears.

Thanks

[PitViper75]

Hey Guys!

I'm in the process of RGB moding a Sony KV-27V42 and am having an issue with sync. I'm trying to do luma/ground soldered right to the back of the S-Video connector. Just getting a scrambled image (set to input 1):

SCART PIN 20 -> SVID PIN 3 (Luma)
SCART PIN 18 -> SVID PIN 1 (Ground Luma)

I didn't feel like pulling the board again so for ha-has I cut a yellow RCA plug, soldered the SYNC wire in there and pugged it in....picture looks beautiful. What am i missing on the SVID? I tried a 75ohm resistor on the line as well.

Thanks!

[PitViper75]

All set - needed to plug something into the s-vid jack for it to work. Also moved the video sync ground (though wasn’t the problem).

[qjkxbmwvz]

All set - needed to plug something into the s-vid jack for it to work. Also moved the video sync ground (though wasn’t the problem).

I recently did a similar set. The S-video connector has a detection pin that connects to ground when the port is in use. I put a short wire between that and the ground pin, which makes S-video always on on Video 1, disabling composite. There's a similar pin in the right audio connector that disconnects it from the left when in use so that you don't get mono when you have the right plugged in - I desoldered that pin, which disabled mono on that input, giving me proper stereo. For the future, I'm planning on rewiring to the unused front input (Video 2). Just need to get a few resistors and caps.

[delibrete]

Hi evryone, Long time lurker (like 20 years), first time poster.

I've successfully RGB modded my Sony KV-G21S11 - Looks absolutely amazing!
Thanks to all the folks that have posted in this thread, I have been silently copying your work
this was also called KV-G21M1, KV-G21P1, KV-G21S1 when sold in other geographies. Its a BG-1S chassis and the jungle is TDA8375

This is about the easiest RGB mod I could hope for.
The S1 chassis has a "teletext" (closed captioning) card in one of the headers, that card header already has RGB and BLK pins, the pins go to an active input on thie jungle, and they already have resistors tied to GND and capicators to tame the signal to what the Jungle expects.
My question is about the BLK voltage;
0-1v = composite
1v - 4v (approx) = RGB (thisi s what i want)
5v+ = blanks everything, no picture
At the moment i've taken 9v off a line on the A board, wired up 3 x LED's in series, this drops the 9v down to approx 3 volts. That works well for BLK

So question is - is there a better way to get approx 3v off this chassis (S1) for BLK without having to wire a whole bunch of LEDs up in series mickey-mouse style.
Or alternatively - other than looking silly is there anything WRONG with having these three LED's in series?

Any thoughts would appreciated.

I'm thinking of picking up this exact CRT model and doing a RGB mod myself. So do you literally just have to connect the scart RGB connections to the RGB on the teletext pins, and connect the BLK pin to a switch? I've been reading up on models with this chassis (BG-S1) and apparently they're super easy because of the teletext pin out.

Forgive me if I'm using the wrong teminology, I've never done anything like this before

[Zabii]

Hello, new here, and new to modding for the most part.

I have a kv-20fs12 I would like to mod, which I saw was in the first page. My plan is to mod this within the next month, does anyone have experience with this set?

[eugen1us]

Hello cyborc,
I'm new to this forum. I was wondering if you were able to successfully mod your Sony KV-27S42 with BA-4D Chassis.

I have a Sony KV-27V66 that uses the same BA-4D chassis and currently looking for a better way to do the RGB mod while preserving the OSD function.

According to TV's service manual, the Jungle chip has an unused RGB input (pin 30-32) and corresponding blanking input (pin 29) but I can't seem to find the datasheet for this Jungle Chip CXA2133S
to confirm if it is digital or analog.

Thanks!

Mark and Syntax,

Thanks so much for the spreadsheet and schematic. Few questions.

The set I plan on modding is a Sony KV-27S42 with BA-4D Chassis.

It has 5.6k ohm resistors on the OSD lines just like the Sanyo in your schematic. However, it also has 680 ohm resistors to ground on each OSD line. Should I remove them?

Also, the jungle blanking input has a 100 ohm resistor, I assume I need to remove that and bridge the pads?

[Azul]

Hello everyone!
I want to do RGB mod on this model KV-29FS140
I have read that in some models it is not possible, will there be a way to do it or will I have to get another TV model?
Service manual here:
https://www.manualslib.com/manual/89763 ... =32#manual

[Cooperd9]

I'm planning out an rgb mod for my GE 31GT659 (uses an RCA CTC187CN chassis), but I'm having a bit of trouble with it. I can find the service manual for a CTC-187 chassis and it has a diagram of the jungle chip, but I haven't done one of these rgb mods before.

Can anyone help me figure out which of these pins is the blanking pin? I would just look up the datasheet for the LA7610 jungle chip to see if that was more clearly labeled, but all I get is a page or two of data sheets for LA7615 that don't seem to match the pinout.