TV RGB mod thread

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meltyzaps
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Re: TV RGB mod thread

Post by meltyzaps »

I picked up a JVC AV-27F577 - hoping to get RGBHV input to use with a Radeon in a PC and crt_emudriver

I think I'm hosed and these F-series TVs aren't going to be candidates. The OSD is done in the all-in-one on the Jungle IC, which I can't find a datasheet for:

Toshiba TM8812CSDNG6H60

Before doing research, I soldered to pins 39, 40, 41 for RGB - 18, 14 for H/V Sync - 29 for ground - hooked that to a VGA cable and it just shuts the tube off to black on connection. Now I'm no surprised as it's obviously (now I see) quite complicated to run the Neck board directly.

Ideas:

Pins 22, 23, 24 on the jungle are YCbCr inputs
* is there possibly a pin to bring high/low on the IC where these can be changed to RGB inputs?
* Maybe I should use these to bypass image processing and at least have cleaner component inputs if RGBHV isn't possible.

ATI/AMD Xilleon 240s Digital ATSC Tuner card (longshot?)
* I don't see how it could be getting RGB signal to the Jungle IC, which I assume it has to go through eventually, but if it bypasses it maybe there is RGB somewhere on this card (or on the socket on the board) I can tap into. Looks like just component and composite stuff here.

Service manual here:

https://usermanual.wiki/Document/AV32F5 ... 832152.pdf

pictures of my work below in spoiler:
Spoiler
Image

Image
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Syntax
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Re: TV RGB mod thread

Post by Syntax »

You could try sweeping 0-5v with a 10k pot on pin 21.

Its the blanking for YUV but its not in use right now, maybe voltage to it will set it into RGB mode.
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cyborc
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Re: TV RGB mod thread

Post by cyborc »

Grabbed a TV from my parents. Toshiba 32A33. Looks really good with component but I want to try RGB on it.

The Jungle ( TA1310N ) has both an OSD rgb AND an RGB input! The RGB input on the tv is "disabled" with a capacitor to ground.

Image

I assume I can just remove those caps and insert my rgb signal there, and send the proper voltage to pin6 for blanking, but will the OSD show up?
Image
[Imgur](https://i.imgur.com/jVF25nc.jpg)


Has anyone successfully modded a tv with this jungle?
meltyzaps
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Re: TV RGB mod thread

Post by meltyzaps »

Thank you Syntax - I will try this and get back to the thread. I assume that I would want to wire up to the YCbCr pins 22, 23, and 24 in this new case, but still use pins 14, 18, and 29 for H/V Sync and ground.

How did you identify that pin as the blanking pin / potential RGB switch pin? I can't find the Toshiba TM8812CSDNG6H60 Datasheet, but I do see in the service manual it is identified as "Ys / Not Used" - does Ys imply blanking?

meltyzaps wrote: ... JVC AV-27F577 ... Toshiba TM8812CSDNG6H60 Jungle IC
meltyzaps wrote: ...

Pins 22, 23, 24 on the jungle are YCbCr inputs
* is there possibly a pin to bring high/low on the IC where these can be changed to RGB inputs?
* Maybe I should use these to bypass image processing and at least have cleaner component inputs if RGBHV isn't possible.


...
Syntax wrote:You could try sweeping 0-5v with a 10k pot on pin 21.

Its the blanking for YUV but its not in use right now, maybe voltage to it will set it into RGB mode.
MarkOZLAD
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Re: TV RGB mod thread

Post by MarkOZLAD »

meltyzaps wrote:Thank you Syntax - I will try this and get back to the thread. I assume that I would want to wire up to the YCbCr pins 22, 23, and 24 in this new case, but still use pins 14, 18, and 29 for H/V Sync and ground.

How did you identify that pin as the blanking pin / potential RGB switch pin? I can't find the Toshiba TM8812CSDNG6H60 Datasheet, but I do see in the service manual it is identified as "Ys / Not Used" - does Ys imply blanking?

meltyzaps wrote: ... JVC AV-27F577 ... Toshiba TM8812CSDNG6H60 Jungle IC
meltyzaps wrote: ...

Pins 22, 23, 24 on the jungle are YCbCr inputs
* is there possibly a pin to bring high/low on the IC where these can be changed to RGB inputs?
* Maybe I should use these to bypass image processing and at least have cleaner component inputs if RGBHV isn't possible.


...
Syntax wrote:You could try sweeping 0-5v with a 10k pot on pin 21.

Its the blanking for YUV but its not in use right now, maybe voltage to it will set it into RGB mode.
From my experience TMPA88xx family of jungles are all Component only. The RGB option was intentionally deleted.
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OSD/External RGB Mux Diagram
OSD/External RGB Mux Resistor Value Table 0.7Vp-p : 0.5Vp-p

"Imagine toggle switch OSD modding a TV in 2019" - maxtherabbit
meltyzaps
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Re: TV RGB mod thread

Post by meltyzaps »

meltyzaps wrote:Thank you Syntax - I will try this and get back to the thread. I assume that I would want to wire up to the YCbCr pins 22, 23, and 24 in this new case, but still use pins 14, 18, and 29 for H/V Sync and ground.

How did you identify that pin as the blanking pin / potential RGB switch pin? I can't find the Toshiba TM8812CSDNG6H60 Datasheet, but I do see in the service manual it is identified as "Ys / Not Used" - does Ys imply blanking?

meltyzaps wrote: ... JVC AV-27F577 ... Toshiba TM8812CSDNG6H60 Jungle IC
meltyzaps wrote: ...

Pins 22, 23, 24 on the jungle are YCbCr inputs
* is there possibly a pin to bring high/low on the IC where these can be changed to RGB inputs?
* Maybe I should use these to bypass image processing and at least have cleaner component inputs if RGBHV isn't possible.


...
Syntax wrote:You could try sweeping 0-5v with a 10k pot on pin 21.

Its the blanking for YUV but its not in use right now, maybe voltage to it will set it into RGB mode.
Tested pins 22, 23, 24 hooked up to my Wii component cable output to confirm wiring / soldering was working. 480p gave a split screen (no progressive support it seems when bypassing all processing?) but 480i gave a picture (see photos), albeit washed out.

Tapped 5v from the 5v regulator, swept 0v - 5v with a 10k pot on pin 21, got nothing but a little bit of fuzz around the edges at full 5v.
MarkOZLAD wrote:
From my experience TMPA88xx family of jungles are all Component only. The RGB option was intentionally deleted.
If that's the case, I'm SOL on this CRT. Let me know if anyone has any other ideas to try - I'm going to sit on it for a few days.

images:
https://imgur.com/a/GTVmBFU
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cyborc
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Re: TV RGB mod thread

Post by cyborc »

This is not my video, just sharing with you guys.

This dude hacks the i2c bus on a sony CRT to enable an external RGB input that is disabled by software. pretty fascinating video.

https://youtu.be/ANSxASanZes
lukilla
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Re: TV RGB mod thread

Post by lukilla »

That was impressive :shock: too bad it requires all of that equipment.
hunkmuffin
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Re: TV RGB mod thread

Post by hunkmuffin »

I've been using up my hoard of spare VGA cables. any 26-28AWG wire should do.
I have this stuff laying around. It is 28AWG. Will it work?

Image
lukilla
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Re: TV RGB mod thread

Post by lukilla »

For internal wiring, you don´t want that for external cable :D
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BobWoggle
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Re: TV RGB mod thread

Post by BobWoggle »

lukilla wrote:For internal wiring, you don´t want that for external cable :D
Internal's what he's asking about, it'll be fine.
:^)
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Syntax
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Re: TV RGB mod thread

Post by Syntax »

Using unsheilded wire means you have to be cautious of what you route your cabling past or else you can introduce interference fairly easily.

When using shielded wire you can bend these rules a bit.
hunkmuffin
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Re: TV RGB mod thread

Post by hunkmuffin »

Syntax wrote:Using unsheilded wire means you have to be cautious of what you route your cabling past or else you can introduce interference fairly easily.

When using shielded wire you can bend these rules a bit.
Is there anything in particular I should try to avoid when routing this cabling as to avoid unwanted interference?
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Syntax
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Re: TV RGB mod thread

Post by Syntax »

The flyback is the main one to steer clear of.

Rf modules can cause interference too

For fun once your mod us running put the sync wire near it and see what happens to your picture.
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Syntax
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Re: TV RGB mod thread

Post by Syntax »

mikejmoffitt wrote:
Syntax wrote:Be nice if someone put it on page 1 so we don't have to dig anymore..
mikejmoffitt wrote:I haven't kept up with this thread because I was getting overwhelmed, and then people started doing shit like tapping into the neck board directly, which this thread was explicitly created to help people avoid doing.

If I have some time I'll parse through where I left off and continue updating the OP.
Four posts ago.
Still waiting for you to add the OSD mux method to the main post mate.

Also waiting for KnuckleheadFlows mux board to be available lol.
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BobWoggle
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Re: TV RGB mod thread

Post by BobWoggle »

Speaking of the OSD mux, I'm wondering about the diodes.

They're there to prevent the OSD resistors from messing with the 75ohm termination, yeah? But if we're just coming straight out of the micon and into a mux sans diodes, how much messing is going to be happening? Even if we've got some termination to ground within the micon's circuitry, you're now terminating external RGB to ground through parallel 75 and 6600+ resistors, that gives you like 74 ohms, what is that going to change?

And if we're putting the diodes after the inlines like the schematic shows, does that not screw with the voltage divider in some way?
(Source Voltage - Diode Voltage Drop) * (Second Inline Resistor + Terminating Resistor)/(First In line Resistor + Second Inline Resistor + Terminating Resistor)
makes it seem like we're dropping the voltage across the diode before it comes into the voltage divider, but the schematic plainly shows the diodes after r1. Am I missing something? Does this not actually change anything?
:^)
Riker
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Re: TV RGB mod thread

Post by Riker »

TylerL wrote:I wanted to say thank you for all the tips learned while lurking this thread, and show off my mod :D
After I was gifted a Sony KV20TR23, I looked up schematics for it online and was surprised to find that it has a (seemingly) rare daughterboard to handle closed captioning. This meant it has an awfully convenient socket on the main board with every necessary pin for analog RGB, fed directly to the Jungle chip. No soldering or board removal necessary!
Image

I spent a good amount of time on eBay and other sites looking for inexpensive SCART parts and accessories for my Genesis, SNES, Wii, and for VGA PC output. It seemed like EuroSCART was the best standard connector to work with.

This surface-mount SCART connector's pins look like they were meant for breadboard connectors...
Here, I've connected RGB along with their separate grounds, as well as the SCART shield ground itself.
Image

Pardon the breadboard mess. I plan to design and solder a nice compact module soon. Then again, I'm very lazy.
Image



Plugged right into the pins on the TV! Couldn't possibly be more convenient (unless, of course, this was a PAL60 TV in the first place...)
I've also tapped into YS and 5V to connect to my breadboard for activating blanking, and chassis ground as well connected to SCART shield ground.
Image

I found a SCART in-line "breakout" adapter that lets me tap into the Composite and Audio signals, which I feed into the traditional inputs on the back of the TV for Sync and Audio. (ignore the cable colors)
Image

Success! And somehow on the first try! Here's a video showing the complete setup, where I toggle the blanking pin high to provide a realtime example of the difference in quality on Sonic 2 through a model 1 Genesis.
https://www.youtube.com/watch?v=4yQHp0pbHMI

Later, I perfected a Linux-based KMS RetroArch install, which feeds a 3840x240 15KHz signal over VGA. Gorgeous and lag-free. For the first time in over a decade, I can play my favorite old fast-twitch and precision platformer games without an emulation delay driving me nuts. Seriously, I've barely been able to enjoy retro gaming before this setup. In fact, the latency is so low, I don't even feel the need for real hardware in most cases!
Image
I've never been an fan of emulator CRT shaders, but the image quality on these ancient games somehow looks high-def on a good Trinitron.

My only issue with the VGA connection is a strange white fringing around high-contrast lines. The checkerboard pattern in the 240p Test SNES ROM looks nearly solid white, for example. Strangely enough, if I pass the VGA single through my Extron (no processing, just passthrough!), the resulting image is perfect. Am I missing something additional that needs to be done (resistors, etc) to the signal? I'd rather cut the Extron our of the chain, obviously...especially since it doesn't really DO anything.

Again, thanks for the insight! If you have any questions or comments, please let me know!
Hello first post.
I have this exact same TV and plan on doing this mod as it looks simple, but i want to wire it to a 4pdt switch, and I'm not sure what wires go where. Is YS the sync wire? if anyone can point me in the right direction that would be great.

This is the switch i have: https://www.amazon.com/gp/product/B01EJ ... UTF8&psc=1
MarkOZLAD
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Re: TV RGB mod thread

Post by MarkOZLAD »

BobWoggle wrote:Speaking of the OSD mux, I'm wondering about the diodes.

They're there to prevent the OSD resistors from messing with the 75ohm termination, yeah? But if we're just coming straight out of the micon and into a mux sans diodes, how much messing is going to be happening? Even if we've got some termination to ground within the micon's circuitry, you're now terminating external RGB to ground through parallel 75 and 6600+ resistors, that gives you like 74 ohms, what is that going to change?

And if we're putting the diodes after the inlines like the schematic shows, does that not screw with the voltage divider in some way?
(Source Voltage - Diode Voltage Drop) * (Second Inline Resistor + Terminating Resistor)/(First In line Resistor + Second Inline Resistor + Terminating Resistor)
makes it seem like we're dropping the voltage across the diode before it comes into the voltage divider, but the schematic plainly shows the diodes after r1. Am I missing something? Does this not actually change anything?

Hey Bob,

I thought of this as I was documenting the mux method. In order to test the maths I used online circuit simulation tools and it turned out that the maths is correct. It's like the diode is directly in front of the 5V even though the resistor is before it. Was very glad that was the case because it made the maths nice and easy.

While we're discussing it, about a month ago I was thinking about the method and realised that the diodes are actually not necessary. So a few tests have been done by both Syntax and myself to prove it and not using the diodes works fine.

You can still use the same spreadsheet to do the calculations, just set the diode voltage drop to zero when working out your resistor sizes. I won't remove the diode field from the spreadsheet because some sets (e.g. TEAC CT-M5122H) have them in place on the chassis from factory.

I will look to publish updated methods soon, including maybe some new thoughts I have on blanking circuits.
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OSD/External RGB Mux Diagram
OSD/External RGB Mux Resistor Value Table 0.7Vp-p : 0.5Vp-p

"Imagine toggle switch OSD modding a TV in 2019" - maxtherabbit
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BobWoggle
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Re: TV RGB mod thread

Post by BobWoggle »

MarkOZLAD wrote: Hey Bob,

I thought of this as I was documenting the mux method. In order to test the maths I used online circuit simulation tools and it turned out that the maths is correct. It's like the diode is directly in front of the 5V even though the resistor is before it. Was very glad that was the case because it made the maths nice and easy.

While we're discussing it, about a month ago I was thinking about the method and realised that the diodes are actually not necessary. So a few tests have been done by both Syntax and myself to prove it and not using the diodes works fine.

You can still use the same spreadsheet to do the calculations, just set the diode voltage drop to zero when working out your resistor sizes. I won't remove the diode field from the spreadsheet because some sets (e.g. TEAC CT-M5122H) have them in place on the chassis from factory.

I will look to publish updated methods soon, including maybe some new thoughts I have on blanking circuits.
Alright cool, I'm not terribly well versed in electronic engineering or anything like that so I wasn't sure if order mattered here, thanks for taking the time to respond.
:^)
MarkOZLAD
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Re: TV RGB mod thread

Post by MarkOZLAD »

BobWoggle wrote: Alright cool, I'm not terribly well versed in electronic engineering or anything like that so I wasn't sure if order mattered here, thanks for taking the time to respond.
No problem at all, good to see someone taking an interest in the method and the math/theory behind it. I'm not an expert either. So glad there were online circuit simulators that I could use to test the theory because I couldn't do it from first principles.
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OSD/External RGB Mux Diagram
OSD/External RGB Mux Resistor Value Table 0.7Vp-p : 0.5Vp-p

"Imagine toggle switch OSD modding a TV in 2019" - maxtherabbit
retrozar
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Re: TV RGB mod thread

Post by retrozar »

Well i managed to mod my tv for RGB easily enough, but could someone help me understand the audio side of things?

I seem to only be getting mono audio (this is a 2 speaker stereo tv) and i have both L/R connected.

I am pulling audio from the bottom of the RCA input stack. I have left audio connected to point 1, right to point 2, and ground to point 4, all of which are going to their respective pins on the scart end. I plugged a bare RCA cable into in each of the top ports and probed with my meter to find these.

What is odd to me is that points 1, 2, & 3 give me a beep when i test continuity between each of them with my meter, yet when i plug in a bare RCA cable to the red (right audio) input on top of the board, point 2 somehow becomes isolated from points 1/3.

Am i supposed to add another ground somewhere or bridge the 3 points? I think the tv is interpreting the signal as mono but needs to be told to use stereo, all of my osd settings are set to stereo though. I dont know much about audio stuff as ive never messed with it before..

https://imgur.com/a/XTKzgic
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Syntax
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Re: TV RGB mod thread

Post by Syntax »

Get an rca plug. Cut the cable off. Stick it in the red rca audio channel.
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BobWoggle
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Re: TV RGB mod thread

Post by BobWoggle »

retrozar wrote:Well i managed to mod my tv for RGB easily enough, but could someone help me understand the audio side of things?

I seem to only be getting mono audio (this is a 2 speaker stereo tv) and i have both L/R connected.

I am pulling audio from the bottom of the RCA input stack. I have left audio connected to point 1, right to point 2, and ground to point 4, all of which are going to their respective pins on the scart end. I plugged a bare RCA cable into in each of the top ports and probed with my meter to find these.

What is odd to me is that points 1, 2, & 3 give me a beep when i test continuity between each of them with my meter, yet when i plug in a bare RCA cable to the red (right audio) input on top of the board, point 2 somehow becomes isolated from points 1/3.

Am i supposed to add another ground somewhere or bridge the 3 points? I think the tv is interpreting the signal as mono but needs to be told to use stereo, all of my osd settings are set to stereo though. I dont know much about audio stuff as ive never messed with it before..

https://imgur.com/a/XTKzgic
Basic mono/stereo detection, when you don't have the right audio jack plugged in it shorts left and right audio to play mono out both speakers. I've been desoldering the jacks, physically removing the pin that shorts across, and then soldering it back in when I come across this. Or you could just plug something in like Syntax said, that works too.
:^)
Geoffrey Beane
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Re: TV RGB mod thread

Post by Geoffrey Beane »

So I have a 20" trinitron i RGB modded. .1uf on the rgb lines, 75ohm to ground. It's composite and RF only so I'm using the rear composite connection for sync.

All of that works fine, connection wise as far as i can tell.

I'm getting an "ok" picture from my genesis, the colors seem to be more vibrant than composite only, a little bit sharper than just composite.

I have 75 ohm resistors inline on the rgb lines, 220uf caps on them and then a 470ohm + 10uf (also tried 220uf) on csync

The rgb works, when i unplug each rgb line, each color set goes away, so i think that's working to some extent.

I've tried using both composite video as sync and csync and neither make a difference in the ghosting around the text. Is this all i can expect for this setup or any tips for getting text that's more clear?

Image
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Derick2k
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Re: TV RGB mod thread

Post by Derick2k »

Man, I am so excited about this thread. Picked up for 4 free 27" sony tv this past weekend that hopefully I can do this mod on. Looking forward to further developments.
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boogiemanspud
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Re: TV RGB mod thread

Post by boogiemanspud »

Image

Image

So I have a Sharp 32UC4. I've been thinking about this mod for a long time but have a couple of questions and want to run this by some folks who have done similar mods. For the R, G, B lines coming from where I mount my female scart connector, they will go to 20, 21, 22 in diagram. Looking at the TB1253AN datasheet, would I lift pins 20, 21, 22? From scart I need a 75 ohm resistor to ground, then a .1uf 16v capacitor in series?

Pin 19 is the YS/YM which should be blanking. So, when I want to blank the screen (so rgb is the whole screen, not just text) I will send 5v to that pin. Does this pin need lifted?

I'm assuming to switch back and forth between the osd and the new rgb input I've made is where the switch will come into play, one way goes to original osd pins that were lifted, the other to the new connections I've made?

Where does the sync line go in this particular chip? Thanks for any help. Also just to assure you, I'm familiar with crt safety and have worked on them and arcade monitors in the past, just never done anything involving injecting signals into ICs. I'm still working my way through this thread but was hoping to clear some things up that I'm foggy on.
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boogiemanspud
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Re: TV RGB mod thread

Post by boogiemanspud »

I've been working on modding a Sharp 32UC4.

Jungle Chip: https://imgur.com/7G758Mp

Jungle Chip Datasheet: https://imgur.com/X4SCavO

I've successfully got the RGB image to show up but it is VERY bright. Is there a simple way to dim it other than the menu settings? I'd like it to be at similar levels as other inputs so I don't have to adjust brightness all the time for different inputs.

Would something like a trim potentiometer work for this? I'm guessing if one were on the R, G, B lines I could turn the pot to set the brightness to a better level. Am I thinking about this wrong?

Also, Looking at the schematics, it looks like pin 20, 21, 22 on the OSD circuit are all terminated with a 680 Ohm resistor. Would I have better luck terminating with a 680 Ohm instead of the 75 Ohm?

I'm very close on the mod and would appreciate it if some more knowledgeable folks could offer some tips on the brightness. Thanks!
djcalle
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Re: TV RGB mod thread

Post by djcalle »

Hi Guys, wanted to run this interesting issue by the group before I give up on this set.

Set: Panasonic TC-14L10A
Chassis: MX-3 https://elektrotanya.com/panasonic_mx3_ ... nload.html
Jungle: AN5192K http://pdf1.alldatasheet.com/datasheet- ... 5192K.html

Status/Issue: The RGB blanks fine with 1.5V but the picture is very dark and very contrasty compared to composite. the screen also goes grey instead of black when the input fades to black.
Please see this video showing the issue:
https://youtu.be/DjSZfEKQ5RE

What I have tried so far:
  • -tried different places to input RGB on the chassis and ended up completely isolating the RGB and YS pins of the jungle from the chassis to rule out the chassis completely
    -add 75R termination which produces an even darker picture
    -add inline 1K pots on RGB line, any additional resistance darkens the picture
    -add inline 1uf caps, no perceivable difference.
I know that people have successfully modded MX3 chassis with AN5192K jungle and the AN5192K datasheet doesn't show any components required on the RGB inputs so it really puzzles me that I can't get a clean input even when completely isolation the jungle from chassis.

Any ideas before I give up?
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boogiemanspud
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Re: TV RGB mod thread

Post by boogiemanspud »

https://imgur.com/7G758Mp

https://imgur.com/X4SCavO

I recently modded a Sharp 32uc4. Did the standard 75 Ohm resistors to ground on R, G, B lines, and the .1uf capacitors right before the jungle chip. It works but the image appears too bright. What's the procedure for dimming it a bit? Would trim pots on the R, G, and B lines work? I can dim it through the menu but I'd like the RGB input level to more closely match the rest of the inputs on the tv.

Right now I'm running sync to the green port on the component inputs. I've not seen anything mentioned (I'm up to page 40 lol) but does the sync line need any kind of components, or is it just the sync line coming from your console?

Thanks for any advice!
Last edited by boogiemanspud on Sun Jul 15, 2018 8:32 pm, edited 1 time in total.
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Pikkon
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Re: TV RGB mod thread

Post by Pikkon »

I know on pal sony crt's most have 100 ohm resisters on the rgb lines but a trim pot will work just as well,also make sure your wiring is not close to the flyback.

As for the sync you don't need anything extra.
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