TV RGB mod thread

[MarkOZLAD]

In fact, I'd love some advice for modding a Samsung HiTron TV-488. I'm not having any luck finding the service manual, but it uses this Philips IC (TDA8841) - https://my.mixtape.moe/hiflqk.pdf.

Hi Buttersoft, I’m also in Australia. I have acquired a TV-348 (14” Samsung) which composite in/out on the back.

It also uses the same Philips jungle IC. 4481. Does this mean my set will also have RGB disabled in the EEPROM?
What’s the easiest way to test this?

It seems like the component plugs are soldered into a SCART pin-out on the PCB. If RGB is active, would this mean a simple desolder and swap in a SCART plug?

Any insight would be great

The set needs to have the scart option set in the service menu.

After that it is a matter of soldering in the scart port and connecting the dots based on schematics.

[ElectroGehirn]

Hello guys, i am new here, just want to ask where i could reach out for help with my philips 19pt825b/00 - fl4.26, not for modding, better said finding a way to get it working again. i was tring watch my vhf signal on air and then it made a poof sound (no cap is broken as it looks rn) and it wont turn on anymore, just showing its red led and giving up when i want to turn it on

[alamone]

Hi, I'm attempting to RGB mod a Sony KV-13M40, it appears to use "BA-4" chassis, the jungle is Sony CXA2061S, the microprocessor is M37273M8.
At the moment, I want to just do a simple mod of replacing the OSD with RGB input without trying to do a mux of the OSD.

I was finally able to get a picture, but the sync is unstable (wavy lines) and there is noise from the OSD.
I lifted the RGB input pins on the jungle, which are connected via 0.01uF caps to RGB output from supergun.
I previously tried connecting these RGB lines to GND via 75 ohm resistors as stated in OP, but this caused the image to be very dark and blurry, so I removed the resistors.
Composite sync is connected to composite video input via 0.01uF cap and 470ohm resistor.
+5V and GND are taken from pins 26 and 27 of the M37273M8.
+5V is tied to YS pin on the jungle via 10k resistor.

Picture from supergun. Note the wavy sync at nose of the plane:


Picture when YS pin enabled and no video input. Note that you can see "Video 1" text clearly:


Wiring to jungle (RGB input and Ys) and microprocessor (+5V and GND):


Am I missing something to stabilize the sync and remove the OSD noise? Thanks for any help.

[alamone]

I was able to fix the OSD ghosting problem by adding back the 75 ohm resistors to GND (I had soldered them in the wrong place, after the caps instead of before the caps).
However I'm having a problem where the screen filckers or blinks around every 2 seconds or so. I posted a video, capturing first with no signal but Ys pin on, and then with signal.

https://youtu.be/HjK6mj7zCkQ

[alamone]

This time instead of connecting CSYNC to the composite input jack, I lifted pin 4 (CVBS) on the jungle and connected it to CSYNC via a 0.01uF cap and 75 (well 83 since I don't have 75) ohm resistor to GND.
That resolved the periodic blinking, but now I'm getting periodic snow, and also some jailbar interference patterns as shown in the video.

https://youtu.be/_OKz93dmdv4

Almost working, but not quite...

[alamone]

OK, I fixed the snow, 5V to the YS pin is apparently too high, I used a voltage divider to reduce to 2.5V and now there are no more artifacts in the signal. For the wavy picture, I was able to reduce the problem by lowering the brightness pot from the HAS. So I finally got it working, next I might try to do a mux mod.

https://x.com/alamone/status/1929657195056205841

[Muzzy011]

Hello all! I recently picked up a couple of RF only sets and have been researching RGB modding them. One is an early 90s Magnavox RR1939C421 that seems to be hot chassis but the other is a newer Sanyo AVM-2508G that looks promising.

The closest manual I can find is https://elektrotanya.com/sanyo_avm-2507 ... nload.html but it appears to be the use the same PCB and ICs. The Jungle IC is LA76070N https://www.scribd.com/doc/202370624/LA76070N .

I checked for resistance between the terminals on the AC plug and the shield around the tuner on the board and it was reading about 0.7 M ohms. It also appears to have a hot "Power" area circled off in the masking on the PCB around the power supply components.

Does this seem like a hot chassis unit or does it look ok to proceed with experimentation? Any additional items I can check to rule out hot chassis? Thanks in advance!

For anyone that finds this in the future, it does seem that this set can be modded (best I can tell its not hot chassis but do your own research before attempting!!!) but unfortunately I damaged it during the process. After some preliminary testing I took the board out again to add diodes to the RGB lines and when going back together I accidentally plugged the degauss coil into the wrong plug (an identical header near the back of the board) and now the image is distorted and black on one side.

Picture of what it looks like now and where on the board I made the mistake - https://imgur.com/a/88660Tt Does it look like a lost cause at this point?

Edit - Its not dead! I was testing it without the grounding resistors added back into the circuit and didn't realize how bad it would look with those missing. Still can't get composite in working but going to wait on additional parts before continuing testing.

Did you ever make it work? I got an exact TV in very good condition, with very good geometry. I also found this link https://sector.sunthar.com/guides/crt-r ... m2507.html, but I can't figure it out. I am not a stranger to electronics, but this is my first TV MOD

[gabrielgamer99]

https://imgur.com/a/XHx8pct

Has anybody seen video interference like this with an rgb mod?

I did an rgb mod on a Mickey Mouse tv and occasionally off and on I’ll get video noise only on the bottom half of the screen, like what’s posted in the photo

I tried my best to follow the path in the photos of the guide, I even went ahead and shielded all the wiring with copper tape, grounding the copper tape, then covering it with harness tape, which I think improved it somewhat

Using snes with high quality scart cables, issue also appears on Saturn rgb (would test with more but don’t have money for good scart cables and no good supplier in Canada)

Issue only appears on rgb, composite looks fine

The author of the original guide didn’t seem to use any fancy cables so not sure why I’m having issues unless a particular cap is bad but doesn’t show up anywhere else

Looking for answers, can probably use as is but if it’s not hard would like to make it so there’s no noise

(Have done two other rgb mods and haven’t had issues like this before)

Thanks for reading!

https://sector.sunthar.com/guides/crt-r ... 1350c.html

Guide I followed

[alamone]

Here's a video of the finished RGB mod for the Sony KV-13M40.

https://x.com/alamone/status/1931854355461963833

I'm using a VGA connector for RGB, I hate bulky SCART ports.

I tried to convert it to a MUX mod. While the OSD does display, it's very faint, but I don't really need to use the OSD much so I'm going to leave it as-is.

[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.

[MarkOZLAD]

I may release the circuit in the future

I for one would love to see the circuit.

Great job.

[Anonygoose]

Looking to RGB mod this Sanyo set (A8-A chassis).

I can see RGB pins from the jungle going to the teletext connector (have not opened CRT yet, not sure if Teletext is populated).

Do I simply inject RGB here and add 75ohm and .1uf caps?



Edit: Opened up the CRT. Teletext is not populated and the 3 1k ground resistors aren't there. So from my understanding I need to populate 75ohm resistors in there, wire blanking to a voltage source along with a switch and I should be good to go. Blanking voltage 2.5-3v (?). Please correct me if I'm wrong.

[esnc68]

Anyone know if I can RGB mod this Panasconic ct-27g24a from 1999?

https://imgur.com/a/crt-pana-2ODwzyX

Is this TV worth RGB modding and can it work good? I tried searching myself. I think I heard somewhere that some Panasonics have a "bump" effect with RGB mod. I was hoping it wasn't the case with this tv. But if so, would it be too bad to be worth it?

And my questions about doing these mods are:

1. I kind of want to do a Scart input. Because I heard it is a little better than component for RGB and sharper. Is that right?

2. If I do scart, will it be able to connect to the tv speakers?

3. Would that be better than AV sound?

I don't know anything about doing this or EE in general, so I was thinking of asking my neighbor to do this.

Anyone have any recommendations or advice to do this? I would love to do this! I love these older round tube tvs the most and I absolutely want to see my games in RGB on it!! I was also thinking of connecting an emulator computer (CRT Emudriver stuff). Or a mister when I get one in the future.

Thank you so much!!

[MarkOZLAD]

Edit: Opened up the CRT. Teletext is not populated and the 3 1k ground resistors aren't there. So from my understanding I need to populate 75ohm resistors in there, wire blanking to a voltage source along with a switch and I should be good to go. Blanking voltage 2.5-3v (?). Please correct me if I'm wrong.

That’s what I’d do.

For the blanking I’d make sure the 1K pulldown is in place for it and then run 5V through a 1K to a switch and then into the blanking. That’ll give you 2.5V.

[Anonygoose]

Edit: Opened up the CRT. Teletext is not populated and the 3 1k ground resistors aren't there. So from my understanding I need to populate 75ohm resistors in there, wire blanking to a voltage source along with a switch and I should be good to go. Blanking voltage 2.5-3v (?). Please correct me if I'm wrong.

That’s what I’d do.

For the blanking I’d make sure the 1K pulldown is in place for it and then run 5V through a 1K to a switch and then into the blanking. That’ll give you 2.5V.

I found a full unpopulated scart circuit



Schematics didn't show this. I'll try populate this

[MarkOZLAD]

I found a full unpopulated scart circuit



Schematics didn't show this. I'll try populate this

I would do the same. Perhaps look for schematics/service manuals for sets with same or similar chassis.

[lazyelm]

Hi - I am trying to mod a KV-27SXR10 - Ive attached the schematic and traced out the lines. this is a p2b chassis - i believe the same as a 25xbr (which has native RGB) and i think it should support rgb injection. I've found a few other sources that say it does (for what its worth). The jungle is a CX848

I have tried injecting rgb and blanking right at the IC301 pins 32,34,34 and Blanking 35 - but im not getting anything yet. Im a bit confused by this diagram as it shows those pins going to the 'New dynamic color' (NDC) IC into the IN RGB pins suggesting the chroma pins are OUT , NOT input signal. Theres also the OSD output going to "out" of the NDC chip as well.

Any thoughts or recommendations would be appreciated

[Delphius]

Hi - I am trying to mod a KV-27SXR10 - Ive attached the schematic and traced out the lines. this is a p2b chassis - i believe the same as a 25xbr (which has native RGB) and i think it should support rgb injection. I've found a few other sources that say it does (for what its worth). The jungle is a CX848

I have tried injecting rgb and blanking right at the IC301 pins 32,34,34 and Blanking 35 - but im not getting anything yet. Im a bit confused by this diagram as it shows those pins going to the 'New dynamic color' (NDC) IC into the IN RGB pins suggesting the chroma pins are OUT , NOT input signal. Theres also the OSD output going to "out" of the NDC chip as well.

Any thoughts or recommendations would be appreciated

At a quick glance it looks like pins 32,33,34 on the CX848 are output pins, not for the OSD input. They go into NW301, then from there it injects with the OSD just before going to the C board. You might be better off trying to inject just before the C board, but double check voltages here. It seems it is expecting around 3v.

[lazyelm]

At a quick glance it looks like pins 32,33,34 on the CX848 are output pins, not for the OSD input. They go into NW301, then from there it injects with the OSD just before going to the C board. You might be better off trying to inject just before the C board, but double check voltages here. It seems it is expecting around 3v.

Thank you. Couple follow up questions. If it’s expecting 3 volts would I need to increase the output voltage of the rgb signal before I inject? If so I think I would need to use an rgb amp circuit?

EDIT: just measured the voltage and I’m seeing .7v there

Injecting before the c board wouldn’t use blanking right? Would I use a switch and just switch between the original signal and the injected one?

[Delphius]

At a quick glance it looks like pins 32,33,34 on the CX848 are output pins, not for the OSD input. They go into NW301, then from there it injects with the OSD just before going to the C board. You might be better off trying to inject just before the C board, but double check voltages here. It seems it is expecting around 3v.

Thank you. Couple follow up questions. If it’s expecting 3 volts would I need to increase the output voltage of the rgb signal before I inject? If so I think I would need to use an rgb amp circuit?

EDIT: just measured the voltage and I’m seeing .7v there

Injecting before the c board wouldn’t use blanking right? Would I use a switch and just switch between the original signal and the injected one?

If you are getting 0.7v ptp at that injection point before then you might be good. It would seem that it has 75ohm termination somewhere on that line already. But the blanking line is a little confusing to me since it isn't being used to control the OSD switching at the jungle chip. It is almost like it is using the transistors to use the blanking lines as bias? I am not really sure, but you might play around with injecting blanking on the pin 43 line of the OSD chip (IC101) if you aren't getting signal. You can observe what pin 43 is doing on that line by measuring it with the OSD turned on and off.

[lazyelm]

If you are getting 0.7v ptp at that injection point before then you might be good. It would seem that it has 75ohm termination somewhere on that line already. But the blanking line is a little confusing to me since it isn't being used to control the OSD switching at the jungle chip. It is almost like it is using the transistors to use the blanking lines as bias? I am not really sure, but you might play around with injecting blanking on the pin 43 line of the OSD chip (IC101) if you aren't getting signal. You can observe what pin 43 is doing on that line by measuring it with the OSD turned on and off.

Thanks - If I am tapping into the connecter that goes out to the C board (which is the neckboard) - and I inject sync on the svideo line - will that sync properly If i am on the right input?

Also - your point about the blanking - trying to understand why I would need to play with blanking - tapping into the line to the Cboard - wouldn't that effectively jump in front of any signal that is being sent to the neck board? -- meaning that blanking would not be needed? I may be misunderstanding though

[Delphius]

If you are getting 0.7v ptp at that injection point before then you might be good. It would seem that it has 75ohm termination somewhere on that line already. But the blanking line is a little confusing to me since it isn't being used to control the OSD switching at the jungle chip. It is almost like it is using the transistors to use the blanking lines as bias? I am not really sure, but you might play around with injecting blanking on the pin 43 line of the OSD chip (IC101) if you aren't getting signal. You can observe what pin 43 is doing on that line by measuring it with the OSD turned on and off.

Thanks - If I am tapping into the connecter that goes out to the C board (which is the neckboard) - and I inject sync on the svideo line - will that sync properly If i am on the right input?

Also - your point about the blanking - trying to understand why I would need to play with blanking - tapping into the line to the Cboard - wouldn't that effectively jump in front of any signal that is being sent to the neck board? -- meaning that blanking would not be needed? I may be misunderstanding though

You might be right about it not needing blanking if you are tapping in before the D board. But I just am not certain. An alternative would be to tap RGB right at the output of the OSD chip (IC101) pins 45-47. But if you follow BLK line from the OSD chip you will also see where it connects to transistor over by the D port connection. These are labeled RGB blanking and it seems to connect those lines to ground when the transistor is activated. I would have to study this more to understand exactly how they are using the circuit, but this might affect it. But adding blanking signal to that line might still trigger some sort of switching to be aware of. If you inject at the OSD points you might need to use that, or the other way around.

[lazyelm]

You might be right about it not needing blanking if you are tapping in before the D board. But I just am not certain. An alternative would be to tap RGB right at the output of the OSD chip (IC101) pins 45-47. But if you follow BLK line from the OSD chip you will also see where it connects to transistor over by the D port connection. These are labeled RGB blanking and it seems to connect those lines to ground when the transistor is activated. I would have to study this more to understand exactly how they are using the circuit, but this might affect it. But adding blanking signal to that line might still trigger some sort of switching to be aware of. If you inject at the OSD points you might need to use that, or the other way around.

Ok I tested a few things

I injected right at the connector going to the d board. With and without trying to use blanking. No result. One thins I noticed is that I’m using an rgb tuner board which has variable pots to dial in the resistor values. Changing the inline and termination values makes the green menu text get brighter


I also tried injecting right at the osd pins. Also no image. Using the pots will make the green text brighter or also reduce it to nothing. So I seem to be able to control the intensity of the menu text but it’s not using the signal I’m injecting


Not sure what to try next. Going to play around more with it tomorrow. It seems like it should be possible though.

[Delphius]

You might be right about it not needing blanking if you are tapping in before the D board. But I just am not certain. An alternative would be to tap RGB right at the output of the OSD chip (IC101) pins 45-47. But if you follow BLK line from the OSD chip you will also see where it connects to transistor over by the D port connection. These are labeled RGB blanking and it seems to connect those lines to ground when the transistor is activated. I would have to study this more to understand exactly how they are using the circuit, but this might affect it. But adding blanking signal to that line might still trigger some sort of switching to be aware of. If you inject at the OSD points you might need to use that, or the other way around.

Ok I tested a few things

I injected right at the connector going to the d board. With and without trying to use blanking. No result. One thins I noticed is that I’m using an rgb tuner board which has variable pots to dial in the resistor values. Changing the inline and termination values makes the green menu text get brighter


I also tried injecting right at the osd pins. Also no image. Using the pots will make the green text brighter or also reduce it to nothing. So I seem to be able to control the intensity of the menu text but it’s not using the signal I’m injecting


Not sure what to try next. Going to play around more with it tomorrow. It seems like it should be possible though.

Seems like the RGB tuner is creating a voltage divider or something. But if it is actually affecting your lines then you might be on the right track. Is there any bias on the lines before you try injecting anything? Measure the voltage where you are injecting and see if there is anything staying steady without any signal passing through. Do menus and other display information look pretty normal when you inject?

[digitron]

Does anyone know how to get into the service menu on a Toshiba C30E50 (TAC 9513 Chassis)? I dug all over the interwebs - Vol down, holding 9 or Mute then hold Mute & Menu don't work.

FOUND IT

Toshiba TV/CRT Service Menu Code Method 2

Turn the TV on.
Press the {MUTE} button three times on the remote.
Press the {MUTE} button again on the remote and hold.
Then press the {MENU} button on the TV's front panel.
Release both buttons
There should be a letter "S" on the upper right of the screen.
Press the {MENU} button on the TV's front panel again.
{CH+} & {CH -} buttons select options
{*VOL+} & {VOL-} buttons change values
To exit, turn the power off.