TV RGB mod thread

[doofy77]

So, I attempted to mod my LG CA-21D33EX today, and was mostly successful, but the OSD Menu is now really dark.




The OSD menu isn't completely black, just very dark and faint


The AV2 is basically black


This set has the MC-84A chassis. I followed the guide here: viewtopic.php?t=60010. I Installed the missing resistor at R557 with 510R, I also had a missing resistor at R234 75R which i installed as well. Instead of bridging J99, I installed a switch so I could switch back and forth between CVBS and RGB. I managed to change the required settings in the service menu but it was pretty difficult to see.



Everything seems to work fine. I can switch between composite and RGB no problem but the OSD menu is almost unreadable.
It isn't just on the AV1 input though, it's on the tuner and on AV2.

Does anyone know what the issue could be?

It looks like the OSD is muxed after the jungle chip.


I checked around the board for any missing components related to the OSD and found that C17 wasn't there. Should I put one there? Should it be the same value as C14, C15, and C16?

[MarkOZLAD]

The jungle chip in this set requires 1-3V for RGB blanking but also has a mode when the blanking goes over 4V where the jungle RGB out is muted for osd overlay. (Due to the post mixed OSD)

Seems likely that you’ve somehow mucked up the blanking circuit such that the OSD blanking is no longer able to go above the 4V, though I cannot be sure.

These are generally about the easiest mod you can ever do so hard to pick what you’ve done wrong. The first thing I can think to do is to check the resistance between pin 16 of scart and ground. Should be 75 ohm.

[Trick-E]

So I'm in the middle of an RGB mod on a JVC C-1327 with the Toshiba TA8601AN Jungle IC, but have yet to see good results.
Has anyone successfully completed a working RGB mod on one of the JVC C series?

I have the chassis schematics, but only the datasheet for the TA8601BN, which is likely similar but not identical.

I've tapped into the RGB output of the Jungle chip (at the resistors just afterwards), and grabbed the Sync and Blanking directly from the chip pins, but don't have a clear signal.

Looks like sync isn't working, and while the screen goes black once I input an RGB signal, this happens whether or not the voltage goes to the blanking, and my input signal is barely visible.

Any help would be appreciated. I can add any necessary pics to clarify this post.

Trick

[ahkek89]

Panasonic TC21S10R with MX-3 chassis

The mod consists of only 3 capacitors, a switch, scart sockets and some cables.
The picture is perfect!
The only drawback is that the service menu does not allow to move the picture a little more to the right, but it is not a problem.
When the OSD is needed, it is turned on by the switch - the green color changes a little, but only for a moment while settings are made.

Is the brightness consistent across different consoles?

[tikao]

Emerson HKTV13 / Hello Kitty TV RGB Mod Update

Just want to give an update on the HKTV13 I was working on. It was a lot of work but I was able to successfully add RGB and find a proper solution around the dual OSD / Switch buffer circuit. I had to isolate them entirely and create my own circuit board with a switching component that 2:1 from the external RGB and the original composite / OSD circuit. I also ended up needing to add an RGB amplifier for the external RGB to give it enough boost to work properly into the jungle chip. It looks pretty damn good and the levels seem spot on so far.



I may release the circuit in the future after I am finished with it. Overall it is pretty non destructive as sort of an interposer board using the wiring harness to inject the signals. I did replace the harness with modern JST connectors to make it more compatible. Next up will be drilling out the holes in the shell for the RCA jacks and switch.

I tried to do the RGB MOD here too and ran into the same problems you imagined. Luckily, I found your posts here and would like to know if you could share the solution you developed.
I've tried several solutions and haven't been able to get a good result.
I'd appreciate it if you could help.

[crowmacnas]

Has anyone tested whether the TA8801AN chip accepts analog OSD or just a digital signal?

Not sure if this is related, but I also have a Toshiba Jungle IC I've been trying to find info on for a RGB mod on a Sony KV20VM30 TV/VCR Combo.
The goal is to add a SCART RGB input.

I know it's been over a year since you posted this, lowonammo, but I'm also working on a TA8825AN chip in a KV20VM30. I think I've about determined that it does not take an analog RGB input but I'd like to hear any updates you have. Did your experiments turn up anything promising?

[pearlito]

Okay, so I'm going to mod my Samsung SMC-150FN CCTV this weekend and I need someone to spot check me at least from a high level (i.e. I'm not worried about voltages and resistor values right this second, just need to know that I'm on the right track.)

I found the Service Manual of the SMC-152FP, which is essentially the same (150 is 2 input, 152 is 4 input, FN is NTSC, FP is PAL).

The jungle chip is a Philips TDA9380PS/N3. It looks like all the OSD processing is done within the jungle chip, so I can't just splice into the OSD lines, BUT it does have empty RGB pins at 46, 47, and 48.

Pin 45 looks like Fast Blanking, which is required to enable the internal RGB input. HOWEVER, it looks from the Data Sheet of the chip that in order for fast blanking to be active, data byte 6 of Control 0 at Slave address 2A, known as IE2, needs to be set to 1, potentially at some interval, though I doubt they apply that value after boot? I would imagine that by default, the fast blanking byte is set to 0.

I've used Arduinos before, and it seems to me like I just have to inject that value on the I2C bus and then activate pin 45 to allow me to use 45, 46, and 47 as RGB, right?

And as a bonus, it looks like if I can toggle the value at D2 of 2B (AKA "YUV" on Control 1), I can swap between RGB and YUV, no?

Here is part of the schematic diagram from the service manual:

Spoiler

Here is the chart of values from the data sheet of the jungle chip:

Spoiler

Here is the description of the values from the same data sheet:

Spoiler

Here is the description of the pins from the data sheet:

Spoiler

Link to the data sheet: https://www.alldatasheet.com/datasheet- ... ASHN2.html

Am I way far off base?

[MarkOZLAD]

I believe this would require the software in the micom part of the chip to be configured for Compoment or RGB. I don’t think you’ll be able to send any i2c commands to enable.

[pearlito]

Is that not just the value at D2 of 2B? "YUV" on Control 1?

[MarkOZLAD]

It is likely that…but modifying that value is the trick. It’s set in the micom software.

[MarkOZLAD]

Is that not just the value at D2 of 2B? "YUV" on Control 1?

I’m not suggesting you don’t try though. Life’s too short to die wondering. Have a crack if you’d like. I’d be happy to be proven wrong.

[Cyberdemon]

Hi, I need help adding RGB to a Sony GP-1A Chassis (Jungle IC CXA1213S). it is possible to do that?
thx!

[MarkOZLAD]

Hi, I need help adding RGB to a Sony GP-1A Chassis (Jungle IC CXA1213S). it is possible to do that?
thx!

It’s a no go with RGB mod through the jungle.

Can be S-Video modded. There’s a whole thread about a similar chassis.

viewtopic.php?t=65583

[Delphius]

Emerson HKTV13 / Hello Kitty TV RGB Mod Update

Just want to give an update on the HKTV13 I was working on. It was a lot of work but I was able to successfully add RGB and find a proper solution around the dual OSD / Switch buffer circuit. I had to isolate them entirely and create my own circuit board with a switching component that 2:1 from the external RGB and the original composite / OSD circuit. I also ended up needing to add an RGB amplifier for the external RGB to give it enough boost to work properly into the jungle chip. It looks pretty damn good and the levels seem spot on so far.



I may release the circuit in the future after I am finished with it. Overall it is pretty non destructive as sort of an interposer board using the wiring harness to inject the signals. I did replace the harness with modern JST connectors to make it more compatible. Next up will be drilling out the holes in the shell for the RCA jacks and switch.

I tried to do the RGB MOD here too and ran into the same problems you imagined. Luckily, I found your posts here and would like to know if you could share the solution you developed.
I've tried several solutions and haven't been able to get a good result.
I'd appreciate it if you could help.

Hello, sorry for the delay on this I wasn't receiving notifications about this post. I will organize some things that will help you out. Did you make any progress? Are you comfortable with building circuit boards?

[tikao]

Hello, sorry for the delay on this I wasn't receiving notifications about this post. I will organize some things that will help you out. Did you make any progress? Are you comfortable with building circuit boards?

Unfortunately, I haven't made any progress. I've tried several solutions, none of them satisfactory.
I know how to build circuits.
Depending on the complexity, it can be difficult, but I'm open to the challenge.

[Delphius]

Hello, sorry for the delay on this I wasn't receiving notifications about this post. I will organize some things that will help you out. Did you make any progress? Are you comfortable with building circuit boards?

Unfortunately, I haven't made any progress. I've tried several solutions, none of them satisfactory.
I know how to build circuits.
Depending on the complexity, it can be difficult, but I'm open to the challenge.

Unfortunately I don't think you can RGB mod this TV with the standard mux technique because the switch that is built into the OSD circuit is active. The mod I designed non destructively taps into CN-101 (if I remember correctly) and allows to switch between standard operation and RGB input. I also found that passive injection of the RGB signal did not provide enough current to give a strong enough signal to the display so I added an amplifier to the mod. This really makes for a nice RGB signal and it probably wouldn't hurt to use an amplifier in other mux mod circuits.

I plan on releasing this mod circuit to the public but I need to finish up some testing. On my original prototype design I learned that the added circuitry created a lot of noise when I shared the TV's existing 5v line so I had to kludge a voltage regulator to tap a dedicated 5v for the mod from the 10v line. The newest revision has a dedicated voltage regulator to do this but I haven't gotten around to testing it yet. In theory the new voltage regulator should work, but I don't want to release the newest design to public until I know for certain it is correct. The mod I did was for a friends TV so I will need to get in touch with him about swapping the old mod with the new one for me to test this properly.

I will have extra mods available that I was thinking about selling as a kit if you are interested in something like that. Or if you have the ability to manufacture and solder your own boards you can wait for the public release and do everything yourself. Everything on the mod board is 0805 surface mount and SOIC type IC's if I remember correctly. Whether you build your own or buy a kit from me, it is recommended that you replace the cables for CN-101 to the neck board to a modern JST connector and cable. I was able to change these out without removing the TVs main board and is the only change that needs to be done on the main board. It can be reversed because the neck board can still attach directly to the main with the JST connectors without the mod board interposing in between. So pretty minimal installation aside from modifying the chassis for RCA or SCART.

On that note, the mod board is designed to support both RCA phono inputs with a switch, or SCART with fast blanking activation. My install used phono RCA with a dedicated switch so I haven't tested the SCART activation, but it shouldn't have any issues as far as I know. The mod also supports injecting audio if you are using SCART. Do you have any thoughts on which you would prefer to use?

[tikao]

Unfortunately I don't think you can RGB mod this TV with the standard mux technique because the switch that is built into the OSD circuit is active. The mod I designed non destructively taps into CN-101 (if I remember correctly) and allows to switch between standard operation and RGB input. I also found that passive injection of the RGB signal did not provide enough current to give a strong enough signal to the display so I added an amplifier to the mod. This really makes for a nice RGB signal and it probably wouldn't hurt to use an amplifier in other mux mod circuits.

I plan on releasing this mod circuit to the public but I need to finish up some testing. On my original prototype design I learned that the added circuitry created a lot of noise when I shared the TV's existing 5v line so I had to kludge a voltage regulator to tap a dedicated 5v for the mod from the 10v line. The newest revision has a dedicated voltage regulator to do this but I haven't gotten around to testing it yet. In theory the new voltage regulator should work, but I don't want to release the newest design to public until I know for certain it is correct. The mod I did was for a friends TV so I will need to get in touch with him about swapping the old mod with the new one for me to test this properly.

I will have extra mods available that I was thinking about selling as a kit if you are interested in something like that. Or if you have the ability to manufacture and solder your own boards you can wait for the public release and do everything yourself. Everything on the mod board is 0805 surface mount and SOIC type IC's if I remember correctly. Whether you build your own or buy a kit from me, it is recommended that you replace the cables for CN-101 to the neck board to a modern JST connector and cable. I was able to change these out without removing the TVs main board and is the only change that needs to be done on the main board. It can be reversed because the neck board can still attach directly to the main with the JST connectors without the mod board interposing in between. So pretty minimal installation aside from modifying the chassis for RCA or SCART.

On that note, the mod board is designed to support both RCA phono inputs with a switch, or SCART with fast blanking activation. My install used phono RCA with a dedicated switch so I haven't tested the SCART activation, but it shouldn't have any issues as far as I know. The mod also supports injecting audio if you are using SCART. Do you have any thoughts on which you would prefer to use?

Thank you very much for the explanations.
I perform maintenance on both retro and modern video game consoles, so I believe I have the necessary knowledge and equipment to manufacture a circuit with surface-mount components (SMD).
I intend to use the SCART connector with fast blanking activation, but I can change to another connector if necessary.

Thank you very much for your help.

[Delphius]

Unfortunately I don't think you can RGB mod this TV with the standard mux technique because the switch that is built into the OSD circuit is active. The mod I designed non destructively taps into CN-101 (if I remember correctly) and allows to switch between standard operation and RGB input. I also found that passive injection of the RGB signal did not provide enough current to give a strong enough signal to the display so I added an amplifier to the mod. This really makes for a nice RGB signal and it probably wouldn't hurt to use an amplifier in other mux mod circuits.

I plan on releasing this mod circuit to the public but I need to finish up some testing. On my original prototype design I learned that the added circuitry created a lot of noise when I shared the TV's existing 5v line so I had to kludge a voltage regulator to tap a dedicated 5v for the mod from the 10v line. The newest revision has a dedicated voltage regulator to do this but I haven't gotten around to testing it yet. In theory the new voltage regulator should work, but I don't want to release the newest design to public until I know for certain it is correct. The mod I did was for a friends TV so I will need to get in touch with him about swapping the old mod with the new one for me to test this properly.

I will have extra mods available that I was thinking about selling as a kit if you are interested in something like that. Or if you have the ability to manufacture and solder your own boards you can wait for the public release and do everything yourself. Everything on the mod board is 0805 surface mount and SOIC type IC's if I remember correctly. Whether you build your own or buy a kit from me, it is recommended that you replace the cables for CN-101 to the neck board to a modern JST connector and cable. I was able to change these out without removing the TVs main board and is the only change that needs to be done on the main board. It can be reversed because the neck board can still attach directly to the main with the JST connectors without the mod board interposing in between. So pretty minimal installation aside from modifying the chassis for RCA or SCART.

On that note, the mod board is designed to support both RCA phono inputs with a switch, or SCART with fast blanking activation. My install used phono RCA with a dedicated switch so I haven't tested the SCART activation, but it shouldn't have any issues as far as I know. The mod also supports injecting audio if you are using SCART. Do you have any thoughts on which you would prefer to use?

Thank you very much for the explanations.
I perform maintenance on both retro and modern video game consoles, so I believe I have the necessary knowledge and equipment to manufacture a circuit with surface-mount components (SMD).
I intend to use the SCART connector with fast blanking activation, but I can change to another connector if necessary.

Thank you very much for your help.

I haven't forgotten about this. The newest revision has been designed and fabrication is on it's way. I cleaned a few things up and added some things that were missing on the original. It might take a couple of weeks to get it tested and hopefully everything will work as expected.

[tikao]

I haven't forgotten about this. The newest revision has been designed and fabrication is on it's way. I cleaned a few things up and added some things that were missing on the original. It might take a couple of weeks to get it tested and hopefully everything will work as expected.

Excellent friend, I will be waiting for updates.

[Mikeyy00]

Hello all, looking for a pointer or two.

Have a Panasonic PV-C1323 crt + vcr combo. Very low hours on the tube, picture looks great. Found the datasheet online easily enough. It has OSD via RGB. IC5301 is the Jungle chip (AN15167A-VT). Looks like pins 27, 28 and 29. Blanking is pin 20. I removed the OEM resistors for the OSD (I'm only ever going to play old games / maybe watch an old VHS, so the OSD doesn't matter to me). Also the OEM resistor for blanking. Wired the blanking pin to Scart 16. Did RGB direct in and 75ohm to ground (initially). Sync via the front Composite port.

Fire up a Genesis 2 using a triple bypass, no caps in the scart cable. I get pretty crispy picture. Test patterns are all good. Sonic looks great.

NES (RGB board inside, with an NES I/O - lets me use the same multi-out as a SNES) I get picture, but it continually rolls / is fuzzy.
SNES (same cable as NES), I get a 99% white washed out white screen. I can barely make out the title screen on Mario RPG.
PS1, no caps in the scart head. Similar to SNES, fully blown out white image. Can barely make out the Sony logo.

I've tried putting 220uf caps in line on the RGB lines (+ side facing console). Various inline resistors (75ohm all the way up to 2k), also have tried different resistors to ground. 75ohm - 2k. None of which really seem to "do" anything? The Genesis still looks great (sometimes the brightness is a tad off), but the other consoles aren't good.

Measuring 2.7v on the sync line from the SNES (composite sync). I think that's too high. But I've tried various combinations of resistors without much luck. Is it possible this TV only takes pure (non composite sync?) I think that's the only difference between my Sega vs the other consoles I have to test (most of them are composite sync).

Anyways, any suggestions are appreciated. Thanks!

[Delphius]

I would try doing some measuring without anything plugged in to the RGB lines and see if you have any voltage bias happening. If the jungle chip inputs are isolated then double check there isn't any bias voltage being generated. Then probe and see what the OSD was originally generating and see what that circuit is doing. Does the OSD generate bias? What type of voltages does it generate when the OSD is present? When you say you remove the OSD resistors, do you mean R5314 - R5316? Are you tapping in to the jungle chip side of those resistors?

Hello all, looking for a pointer or two.

Have a Panasonic PV-C1323 crt + vcr combo. Very low hours on the tube, picture looks great. Found the datasheet online easily enough. It has OSD via RGB. IC5301 is the Jungle chip (AN15167A-VT). Looks like pins 27, 28 and 29. Blanking is pin 20. I removed the OEM resistors for the OSD (I'm only ever going to play old games / maybe watch an old VHS, so the OSD doesn't matter to me). Also the OEM resistor for blanking. Wired the blanking pin to Scart 16. Did RGB direct in and 75ohm to ground (initially). Sync via the front Composite port.

Fire up a Genesis 2 using a triple bypass, no caps in the scart cable. I get pretty crispy picture. Test patterns are all good. Sonic looks great.

NES (RGB board inside, with an NES I/O - lets me use the same multi-out as a SNES) I get picture, but it continually rolls / is fuzzy.
SNES (same cable as NES), I get a 99% white washed out white screen. I can barely make out the title screen on Mario RPG.
PS1, no caps in the scart head. Similar to SNES, fully blown out white image. Can barely make out the Sony logo.

I've tried putting 220uf caps in line on the RGB lines (+ side facing console). Various inline resistors (75ohm all the way up to 2k), also have tried different resistors to ground. 75ohm - 2k. None of which really seem to "do" anything? The Genesis still looks great (sometimes the brightness is a tad off), but the other consoles aren't good.

Measuring 2.7v on the sync line from the SNES (composite sync). I think that's too high. But I've tried various combinations of resistors without much luck. Is it possible this TV only takes pure (non composite sync?) I think that's the only difference between my Sega vs the other consoles I have to test (most of them are composite sync).

Anyways, any suggestions are appreciated. Thanks!

[Mikeyy00]

I would try doing some measuring without anything plugged in to the RGB lines and see if you have any voltage bias happening. If the jungle chip inputs are isolated then double check there isn't any bias voltage being generated. Then probe and see what the OSD was originally generating and see what that circuit is doing. Does the OSD generate bias? What type of voltages does it generate when the OSD is present? When you say you remove the OSD resistors, do you mean R5314 - R5316? Are you tapping in to the jungle chip side of those resistors?

Hello all, looking for a pointer or two.

Have a Panasonic PV-C1323 crt + vcr combo. Very low hours on the tube, picture looks great. Found the datasheet online easily enough. It has OSD via RGB. IC5301 is the Jungle chip (AN15167A-VT). Looks like pins 27, 28 and 29. Blanking is pin 20. I removed the OEM resistors for the OSD (I'm only ever going to play old games / maybe watch an old VHS, so the OSD doesn't matter to me). Also the OEM resistor for blanking. Wired the blanking pin to Scart 16. Did RGB direct in and 75ohm to ground (initially). Sync via the front Composite port.

Fire up a Genesis 2 using a triple bypass, no caps in the scart cable. I get pretty crispy picture. Test patterns are all good. Sonic looks great.

NES (RGB board inside, with an NES I/O - lets me use the same multi-out as a SNES) I get picture, but it continually rolls / is fuzzy.
SNES (same cable as NES), I get a 99% white washed out white screen. I can barely make out the title screen on Mario RPG.
PS1, no caps in the scart head. Similar to SNES, fully blown out white image. Can barely make out the Sony logo.

I've tried putting 220uf caps in line on the RGB lines (+ side facing console). Various inline resistors (75ohm all the way up to 2k), also have tried different resistors to ground. 75ohm - 2k. None of which really seem to "do" anything? The Genesis still looks great (sometimes the brightness is a tad off), but the other consoles aren't good.

Measuring 2.7v on the sync line from the SNES (composite sync). I think that's too high. But I've tried various combinations of resistors without much luck. Is it possible this TV only takes pure (non composite sync?) I think that's the only difference between my Sega vs the other consoles I have to test (most of them are composite sync).

Anyways, any suggestions are appreciated. Thanks!

Hey,

Yes to removing R531416, and tapped into the side facing the jungle. Reading the old OSD points is pretty tricky.. they're on the bottom of the board, so the who board needs to come out, CRT disconnected. VCR disassembled and removed, then I can flip it over.

Even if that was happening, how is the Genesis working without issue?

[Delphius]

Just measure it from the other side of resistors R5314 - 16 / the opposite side of where you tapped into the jungle chip. Getting information on what was originally happening or what type of signal it uses might be helpful. If OSD or the jungle chip is generating bias or not can be helpful in knowing if there needs to be a bias or if it needs coupling. If it needs a bias then and there isn't one then I think it can technically leave the signals floating which means it has no reference and it will vary depending on what is plugged into it.

I am no expert, but the more information the better.

I would try doing some measuring without anything plugged in to the RGB lines and see if you have any voltage bias happening. If the jungle chip inputs are isolated then double check there isn't any bias voltage being generated. Then probe and see what the OSD was originally generating and see what that circuit is doing. Does the OSD generate bias? What type of voltages does it generate when the OSD is present? When you say you remove the OSD resistors, do you mean R5314 - R5316? Are you tapping in to the jungle chip side of those resistors?

Hello all, looking for a pointer or two.

Have a Panasonic PV-C1323 crt + vcr combo. Very low hours on the tube, picture looks great. Found the datasheet online easily enough. It has OSD via RGB. IC5301 is the Jungle chip (AN15167A-VT). Looks like pins 27, 28 and 29. Blanking is pin 20. I removed the OEM resistors for the OSD (I'm only ever going to play old games / maybe watch an old VHS, so the OSD doesn't matter to me). Also the OEM resistor for blanking. Wired the blanking pin to Scart 16. Did RGB direct in and 75ohm to ground (initially). Sync via the front Composite port.

Fire up a Genesis 2 using a triple bypass, no caps in the scart cable. I get pretty crispy picture. Test patterns are all good. Sonic looks great.

NES (RGB board inside, with an NES I/O - lets me use the same multi-out as a SNES) I get picture, but it continually rolls / is fuzzy.
SNES (same cable as NES), I get a 99% white washed out white screen. I can barely make out the title screen on Mario RPG.
PS1, no caps in the scart head. Similar to SNES, fully blown out white image. Can barely make out the Sony logo.

I've tried putting 220uf caps in line on the RGB lines (+ side facing console). Various inline resistors (75ohm all the way up to 2k), also have tried different resistors to ground. 75ohm - 2k. None of which really seem to "do" anything? The Genesis still looks great (sometimes the brightness is a tad off), but the other consoles aren't good.

Measuring 2.7v on the sync line from the SNES (composite sync). I think that's too high. But I've tried various combinations of resistors without much luck. Is it possible this TV only takes pure (non composite sync?) I think that's the only difference between my Sega vs the other consoles I have to test (most of them are composite sync).

Anyways, any suggestions are appreciated. Thanks!

Hey,

Yes to removing R531416, and tapped into the side facing the jungle. Reading the old OSD points is pretty tricky.. they're on the bottom of the board, so the who board needs to come out, CRT disconnected. VCR disassembled and removed, then I can flip it over.

Even if that was happening, how is the Genesis working without issue?

[Mikeyy00]

Just measure it from the other side of resistors R5314 - 16 / the opposite side of where you tapped into the jungle chip. Getting information on what was originally happening or what type of signal it uses might be helpful. If OSD or the jungle chip is generating bias or not can be helpful in knowing if there needs to be a bias or if it needs coupling. If it needs a bias then and there isn't one then I think it can technically leave the signals floating which means it has no reference and it will vary depending on what is plugged into it.

I am no expert, but the more information the better.

I would try doing some measuring without anything plugged in to the RGB lines and see if you have any voltage bias happening. If the jungle chip inputs are isolated then double check there isn't any bias voltage being generated. Then probe and see what the OSD was originally generating and see what that circuit is doing. Does the OSD generate bias? What type of voltages does it generate when the OSD is present? When you say you remove the OSD resistors, do you mean R5314 - R5316? Are you tapping in to the jungle chip side of those resistors?

Hey,

Yes to removing R531416, and tapped into the side facing the jungle. Reading the old OSD points is pretty tricky.. they're on the bottom of the board, so the who board needs to come out, CRT disconnected. VCR disassembled and removed, then I can flip it over.

Even if that was happening, how is the Genesis working without issue?

Looks like ~5v on the RGB lines pre 2700k resistors.

[Delphius]

Try something like this and see if it helps.

External RGB -> 1uf ceramic in series -> 470 - 2.7k resistor series -> 10k pull-down to ground -> Jungle RGB Input

You might have to play around with the resistor values, but that should hopefully give you a good starting point. 2.7k series might be too high but if the OSD output puts out a 0.7v ptp it might actually match the consoles.

Just measure it from the other side of resistors R5314 - 16 / the opposite side of where you tapped into the jungle chip. Getting information on what was originally happening or what type of signal it uses might be helpful. If OSD or the jungle chip is generating bias or not can be helpful in knowing if there needs to be a bias or if it needs coupling. If it needs a bias then and there isn't one then I think it can technically leave the signals floating which means it has no reference and it will vary depending on what is plugged into it.

I am no expert, but the more information the better.

Hey,

Yes to removing R531416, and tapped into the side facing the jungle. Reading the old OSD points is pretty tricky.. they're on the bottom of the board, so the who board needs to come out, CRT disconnected. VCR disassembled and removed, then I can flip it over.

Even if that was happening, how is the Genesis working without issue?

Looks like ~5v on the RGB lines pre 2700k resistors.

[Delphius]

A little more info if you are wondering about my suggestion. The jungle chip seems to be high impedance which is why the OSD is using values like 2.7k and not using lower impedance like 75r or termination. The 2.7k series resistors probably create a voltage divider that matches the correct levels that the jungle chip expects (maybe around 100k input impedance?). Because of this you do not need to use coupling capacitors as high as 220uf because the roll off for that is tuned for a 75r low impedance. 1uf is common for high impedance jungle chips from what I have found and should place the roll off well below any issues. Ceramics are good because they a non-polarized which can be important for this role. The 2.7k / series capacitor should help control the current from your external RGB and assuming the OSD matches to 0.7v / what the jungle chip expects I think this should put you in the ball park. Then probably the biggest thing is the 10 - 47k pull down on the jungle chip side / after the coupling which the jungle biasing needs to establish a reference to ground / 0v. You want this high enough so it doesn't affect your voltage divider too much and also not add to your load to the external RGB, but if this is not in place it leaves the circuit floating. The jungle chips internal clamping tries to establish this ground reference and if it can't then you will get certain issues like the ones you have been experiencing.

It might require some tweaking still and I am not an expert, but this might at least get you in the ball park and remove some of the issues you have been having. Maybe someone else can elaborate on some of this or give a more accurate opinion.

Try something like this and see if it helps.

External RGB -> 1uf ceramic in series -> 470 - 2.7k resistor series -> 10k pull-down to ground -> Jungle RGB Input

You might have to play around with the resistor values, but that should hopefully give you a good starting point. 2.7k series might be too high but if the OSD output puts out a 0.7v ptp it might actually match the consoles.

Just measure it from the other side of resistors R5314 - 16 / the opposite side of where you tapped into the jungle chip. Getting information on what was originally happening or what type of signal it uses might be helpful. If OSD or the jungle chip is generating bias or not can be helpful in knowing if there needs to be a bias or if it needs coupling. If it needs a bias then and there isn't one then I think it can technically leave the signals floating which means it has no reference and it will vary depending on what is plugged into it.

I am no expert, but the more information the better.

Looks like ~5v on the RGB lines pre 2700k resistors.

[Delphius]

Making some progress with this, I just finished soldering up my newest revision for this mod. I am also finishing up some servicing and modding a PS2 slim for my friend with the HKTV13 so I am going to ask him to bring the TV for a swap out when he picks up the PS2. Probably this weekend or early next week. If everything works as planned then I will start prepping everything for public release.

I haven't forgotten about this. The newest revision has been designed and fabrication is on it's way. I cleaned a few things up and added some things that were missing on the original. It might take a couple of weeks to get it tested and hopefully everything will work as expected.

Excellent friend, I will be waiting for updates.

[tikao]

Making some progress with this, I just finished soldering up my newest revision for this mod. I am also finishing up some servicing and modding a PS2 slim for my friend with the HKTV13 so I am going to ask him to bring the TV for a swap out when he picks up the PS2. Probably this weekend or early next week. If everything works as planned then I will start prepping everything for public release.

Thank you again for your reply, I'm looking forward to it.

[SG-17]

I'm debating on if I want to mux mod my Toshiba 14AF43. It does have component and that component does look really good. I suppose when I eventually get around to recapping it, installing a mux mod won't be too much of an extra burden.

[vol.2]

I'm debating on if I want to mux mod my Toshiba 14AF43. It does have component and that component does look really good. I suppose when I eventually get around to recapping it, installing a mux mod won't be too much of an extra burden.

Not worth it. For component capable consoles, it doesn't offer a tangible improvement. For RGB only consoles, I would just use a retrotink RGB2COMP. The cost of one is low enough that you're time is more valuable.