TV RGB mod thread

[realm]

Can you describe your blanking circuit?

I got my 5V source for my blanking circuit from pin 1 of IC101 which is a 5V voltage regulator. I have that wired to a switch that sends the 5V to the blanking pin on the jungle chip. I have the wire from the switch soldered directly to the jungle chips blanking pin. The wire has a 75R terminating resistor and a 3.3k inline resistor which was the value of the terminating resistor that I removed from the OSD blanking circuit.

[matt]

Those Sharp TVs are quirky. RGB is extremely dark compared with composite if you use the usual 75 ohm terminating resistors. Also, as you've found out, this jungle chip doesn't adjust the OSD brightness with the user menu so you're stuck with whatever you've got.

The quick & dirty way to compensate for this is to go into the service menu and increase the RGB cutoff values so that you have the right black level. Then, turning down sub-brightness will darken the composite signal to match. There's still no way to quickly adjust the RGB brightness, which can be frustrating since it changes as the tube warms up.

You could also increase the value of the terminating resistors, but the previous solution worked well enough for me that I haven't worked on it any further.

[realm]

Those Sharp TVs are quirky. RGB is extremely dark compared with composite if you use the usual 75 ohm terminating resistors. Also, as you've found out, this jungle chip doesn't adjust the OSD brightness with the user menu so you're stuck with whatever you've got.

The quick & dirty way to compensate for this is to go into the service menu and increase the RGB cutoff values so that you have the right black level. Then, turning down sub-brightness will darken the composite signal to match. There's still no way to quickly adjust the RGB brightness, which can be frustrating since it changes as the tube warms up.

You could also increase the value of the terminating resistors, but the previous solution worked well enough for me that I haven't worked on it any further.

Thanks for the suggestions. I built my OSD RGB Mux circuit on a proto board so I can remove the board easily and swap out the terminating resistors. I would rather go that route and get it looking the best I can without using the service menu. Then make fine adjustments with the service menu if needed. What terminating resistor values would you suggest changing to?

[matt]

You'll have to experiment. As I mentioned, I didn't pursue that avenue far enough to figure out the right resistor values.

[Daripa]

Can you describe your blanking circuit?

I got my 5V source for my blanking circuit from pin 1 of IC101 which is a 5V voltage regulator. I have that wired to a switch that sends the 5V to the blanking pin on the jungle chip. I have the wire from the switch soldered directly to the jungle chips blanking pin. The wire has a 75R terminating resistor and a 3.3k inline resistor which was the value of the terminating resistor that I removed from the OSD blanking circuit.

Why not use trim pots in your circuit board With a resistor with the max resistance you think you want across/ parallel to the pots.

[realm]

Can you describe your blanking circuit?

I got my 5V source for my blanking circuit from pin 1 of IC101 which is a 5V voltage regulator. I have that wired to a switch that sends the 5V to the blanking pin on the jungle chip. I have the wire from the switch soldered directly to the jungle chips blanking pin. The wire has a 75R terminating resistor and a 3.3k inline resistor which was the value of the terminating resistor that I removed from the OSD blanking circuit.

Why not use trim pots in your circuit board With a resistor with the max resistance you think you want across/ parallel to the pots.

That's so weird I am literally on mouser right now looking for trim pots. I was going to replace the 75R terminating resistors with 100R just to see how much of a difference it makes. I'm not sure how much I should be increasing the resistance so I figured I would try that first.

[Daripa]

I have rgb modded a Panasonic TC-29FX32L, but as you can see in the following videos, I can only get the V-Sync to work:
https://drive.google.com/file/d/1puSl3y ... sp=sharing

There's no hardware problem, the mod is just fine. By the way, the service manual says the RGB is analog.

Maybe it's disabled by software?

Service Manual:
https://drive.google.com/file/d/1noXKmZ ... sp=sharing

I'm sorry for the idiom, the service manual is in Portuguese and I couldn't find it in English anywhere.


Should I enable it by messing with the memory editor? Or by adjusting the service menu options? Is there any guide teaching how?

Post the data sheet for your junglechip. It should have some examples in it.

[realm]

The jungle chip is a Sharp IX3253CE. I can't find a data sheet on that particular chip but @MarkOZLAD said it is a clone of a Toshiba TA1268N I found the data sheet for that chip if that helps. https://datasheetspdf.com/pdf-file/4929 ... /TA1268N/1

[Daripa]

I got my 5V source for my blanking circuit from pin 1 of IC101 which is a 5V voltage regulator. I have that wired to a switch that sends the 5V to the blanking pin on the jungle chip. I have the wire from the switch soldered directly to the jungle chips blanking pin. The wire has a 75R terminating resistor and a 3.3k inline resistor which was the value of the terminating resistor that I removed from the OSD blanking circuit.

Why not use trim pots in your circuit board With a resistor with the max resistance you think you want across/ parallel to the pots.

That's so weird I am literally on mouser right now looking for trim pots. I was going to replace the 75R terminating resistors with 100R just to see how much of a difference it makes. I'm not sure how much I should be increasing the resistance so I figured I would try that first.

Leave the 75 ohm on the RGB lines in there!!! and add the trim in series to it

[realm]

Ok, I'm not sure which trim pot to get, could you suggest something that will work?

[Daripa]

Ok, I'm not sure which trim pot to get, could you suggest something that will work?

I'd start with a 50ohm trim those blue ones with the screw.
Start small.

[realm]

Ok, I'm not sure which trim pot to get, could you suggest something that will work?

I'd start with a 50ohm trim those blue ones with the screw.
Start small.

Something like these? https://www.mouser.com/ProductDetail/Bo ... ALEmsng%3D or these? https://www.mouser.com/ProductDetail/Bo ... sVmird4%3D

[MarkOZLAD]

Well I'm about out of ideas spikespiegel.

How can I check the software for the RGB part? To enable/disable. I know how to get into both service menu and memory editor, but I don't have an actual documentation to look at.

Anyone have any documentation, guide, something like that, that I could use as a reference to edit the memory values just so I could enable the RGB?

Micronas VCT49XYL Datasheet

[isolenz]

Hi All, First time poster, long time reader.

I just picked up a samsung txj2550. It has a TDA8373. I believe I have the proper pins nailed down (Pins 23,24,25 and 26 (blanking)).

The RGB voltage (based on the schematic for my tv) looks to be 3.3V, and I plan on using this primarily for JAMMA based boards which I understand are 0 -> 4V. I may want to use this down the road for SCART voltages in the future too though, which I understand top out at 0.7v.
I also have a PARSEC supergun which seems to output 0.7v RGB through it's BH7236AF IC which is an option for running my JAMMA based boards.

How should I handle this situation? Should I target a common input of 0.7v regardless of the situation and amplify the signal to 3.3v for the TDA8373? Or would I get better quality putting in multiple lines, one for JAMMA and bring it down a smidge, and another for other sources that I would need to amplify up?

Thanks!

https://datasheetspdf.com/pdf-file/325258/NXP/TDA8373/1

TDA8373 accepts 0.7Vp-p RGB via pins 23,24 and 25. (see page 3 of the TDA837x datasheet V23-25 RGB input voltage)

I don't know exactly what the 3.3V that shows on the Samsung schematic against those pins refers to. Some kind of maximum rating or something. See it in other schematics too but have never been sure what it means.

Blanking is 0.9-3.0V on pin 26. (page 31)

Use the supergun to attenuate the Jamma RGB to 0.7Vp-p. You'll be ready for scart voltages then too.

Thank you!

Alright, a semi long story to this, I did the above, and misread 33v on the board as 3.3v (I suppose I'm not used to older high voltage electronics), hooked up it up to the blanking line and blew the tda8373. I got a new tda8373 in yesterday from aliexpress, replaced it, and whamo, I'm back in business!
This time though, I've got a 5v -> 3v buck converter, hooked it up to pin 26, and now when I flip the toggle switch, I get the darkest image ever, to say that it's faint is an understatement (I can see that text is there, but I'm unable to read it).
I hooked up the 75ohm resistors to the rgb lines coming in and then to ground, I've also adjusted the pots on my parsec all the way for the 3, not much difference.
Any idea where I should look here?

Just a couple other notes, composite video works perfectly from the parsec. Also, something aside, I noticed that when I have my switch to revert my TV to regular viewing, when I flip the supergun on, my OSD flickers fast, is this possibly due to the csync signal coming in?

Please see the image here where I cut into the lines

https://ibb.co/CVCJ3dC

Thanks again!

[Daripa]

The jungle chip is a Sharp IX3253CE. I can't find a data sheet on that particular chip but @MarkOZLAD said it is a clone of a Toshiba TA1268N I found the data sheet for that chip if that helps. https://datasheetspdf.com/pdf-file/4929 ... /TA1268N/1

According to this you need 4.7 k ohms to ground on blanking line. Does your TV have av inputs? Switch your TV to av otherwise you won't have sync. Study the data sheet and compare the second last page to the mux diagrams.

[Daripa]

Ok, I'm not sure which trim pot to get, could you suggest something that will work?

I'd start with a 50ohm trim those blue ones with the screw.
Start small.

Something like these? https://www.mouser.com/ProductDetail/Bo ... ALEmsng%3D or these? https://www.mouser.com/ProductDetail/Bo ... sVmird4%3D

The pots are temporary so you can get the correct resistance. Adjusting them all is a painful process from my experience with arcade monitors.

[realm]

According to this you need 4.7 k ohms to ground on blanking line. Does your TV have av inputs? Switch your TV to av otherwise you won't have sync. Study the data sheet and compare the second last page to the mux diagrams.

The pots are temporary so you can get the correct resistance. Adjusting them all is a painful process from my experience with arcade monitors.

So one pot for each terminating resistor? I'm a little confused. Each line, RGB and Blanking will have a pot inline to the terminating resistor? Also according to the OSD RGB Mux circuit 75R resistors are being used for the terminating resistors on the injected RGB lines and blanking line. Is this correct? The value of the inline resistor on the injected blanking line is 3.3k which was the value of the terminating resistor I removed from the blanking line in the OSD circuit. You're saying according to the data sheet it should be 4.7k?

[Daripa]

According to this you need 4.7 k ohms to ground on blanking line. Does your TV have av inputs? Switch your TV to av otherwise you won't have sync. Study the data sheet and compare the second last page to the mux diagrams.

The pots are temporary so you can get the correct resistance. Adjusting them all is a painful process from my experience with arcade monitors.

So one pot for each terminating resistor? I'm a little confused. Each line, RGB and Blanking will have a pot inline to the terminating resistor? Also according to the OSD RGB Mux circuit 75R resistors are being used for the terminating resistors on the injected RGB lines and blanking line. Is this correct? The value of the inline resistor on the injected blanking line is 3.3k which was the value of the terminating resistor I removed from the blanking line in the OSD circuit. You're saying according to the data sheet it should be 4.7k?

It all depends on your setup. The RGB in in the data sheet calls for 4.7k on the fblk but if your not using the RGB in and using the osd in then the values usually differ. If blanking is working as expected leave it alone I just mentioned it incase all else fails :p.


The pots in the RGB lines in series with the 75ohm would give you a total of 125ohms maxed out,
As you increase the pots more goes to the jungle, like building a dam wall to block the flow to ground.

[Daripa]

Btw I just noticed I asked spike from bebop for the data sheet not realm now I'm getting confused.
He is having troubles with sync.

[realm]

It all depends on your setup. The RGB in in the data sheet calls for 4.7k on the fblk but if your not using the RGB in and using the osd in then the values usually differ. If blanking is working as expected leave it alone I just mentioned it incase all else fails :p.


The pots in the RGB lines in series with the 75ohm would give you a total of 125ohms maxed out,
As you increase the pots more goes to the jungle, like building a dam wall to block the flow to ground.

Ok got it, thanks.

[isolenz]

Hi All, First time poster, long time reader.

I just picked up a samsung txj2550. It has a TDA8373. I believe I have the proper pins nailed down (Pins 23,24,25 and 26 (blanking)).

The RGB voltage (based on the schematic for my tv) looks to be 3.3V, and I plan on using this primarily for JAMMA based boards which I understand are 0 -> 4V. I may want to use this down the road for SCART voltages in the future too though, which I understand top out at 0.7v.
I also have a PARSEC supergun which seems to output 0.7v RGB through it's BH7236AF IC which is an option for running my JAMMA based boards.

How should I handle this situation? Should I target a common input of 0.7v regardless of the situation and amplify the signal to 3.3v for the TDA8373? Or would I get better quality putting in multiple lines, one for JAMMA and bring it down a smidge, and another for other sources that I would need to amplify up?

Thanks!

https://datasheetspdf.com/pdf-file/325258/NXP/TDA8373/1

TDA8373 accepts 0.7Vp-p RGB via pins 23,24 and 25. (see page 3 of the TDA837x datasheet V23-25 RGB input voltage)

I don't know exactly what the 3.3V that shows on the Samsung schematic against those pins refers to. Some kind of maximum rating or something. See it in other schematics too but have never been sure what it means.

Blanking is 0.9-3.0V on pin 26. (page 31)

Use the supergun to attenuate the Jamma RGB to 0.7Vp-p. You'll be ready for scart voltages then too.

Thank you!

Alright, a semi long story to this, I did the above, and misread 33v on the board as 3.3v (I suppose I'm not used to older high voltage electronics), hooked up it up to the blanking line and blew the tda8373. I got a new tda8373 in yesterday from aliexpress, replaced it, and whamo, I'm back in business!
This time though, I've got a 5v -> 3v buck converter, hooked it up to pin 26, and now when I flip the toggle switch, I get the darkest image ever, to say that it's faint is an understatement (I can see that text is there, but I'm unable to read it).
I hooked up the 75ohm resistors to the rgb lines coming in and then to ground, I've also adjusted the pots on my parsec all the way for the 3, not much difference.
Any idea where I should look here?

Just a couple other notes, composite video works perfectly from the parsec. Also, something aside, I noticed that when I have my switch to revert my TV to regular viewing, when I flip the supergun on, my OSD flickers fast, is this possibly due to the csync signal coming in?

Please see the image here where I cut into the lines

https://ibb.co/CVCJ3dC

Thanks again!

I figured it out. I still wasn't getting any voltage to my blanking pin. (First I threw 33v at it, then next pass nothing.... jeez). Anyways, I hooked up a couple AA's into it and it works!, super clear picture now. So happy, but I still can't believe how much time I threw into this..... but still so rewarding. Thanks all for the research and work you've all put into this.

[billybob884]

Hello, I have a little Toshiba 13A26 I was hoping to RGB mod. Looking at the service manual I see the RGB out from the main IC (pins 50-52), but I think this might have the jungle chip integrated into the processor? Can anyone tell me if I'm wrong?
https://imgur.com/a/uZ8SCBE

Thank you for your help

[MarkOZLAD]

Hello, I have a little Toshiba 13A26 I was hoping to RGB mod. Looking at the service manual I see the RGB out from the main IC (pins 50-52), but I think this might have the jungle chip integrated into the processor? Can anyone tell me if I'm wrong?
https://imgur.com/a/uZ8SCBE

Thank you for your help

OSD is integrated into jungle and I cannot see another set of RGB inputs. Looks a no go.

[Daripa]

It all depends on your setup. The RGB in in the data sheet calls for 4.7k on the fblk but if your not using the RGB in and using the osd in then the values usually differ. If blanking is working as expected leave it alone I just mentioned it incase all else fails :p.


The pots in the RGB lines in series with the 75ohm would give you a total of 125ohms maxed out,
As you increase the pots more goes to the jungle, like building a dam wall to block the flow to ground.

Ok got it, thanks.

Seems I have the same problem. Screen is very dark, lowering contrast makes it go away. I also adjusted the flyback a little.

[billybob884]

OSD is integrated into jungle and I cannot see another set of RGB inputs. Looks a no go.

Darn, that's what I figured. Thanks for the quick reply at least

[realm]

Seems I have the same problem. Screen is very dark, lowering contrast makes it go away. I also adjusted the flyback a little.

I ended up going with 200R resistors for the terminating resistors on the injected RGB lines and made the slightest adjustment on the flyback and it looks great.

[Daripa]

Also struggled with my set, was very dark. I doubled the terminating resistors, rerouted a few grounds and cut traces incase I bodged something,replaced caps, played around with the blanking circuit, adjusted the flyback, used Luma sync. Nothing worked.

Turns out the cable I made for my Wii was at fault made one for the PS and now it looks slot better. When I get a remote for this TV I'll calibrate it. Got a bit of interference on the right hand side but I'm not opening her up again.

[Daripa]

Could anyone tell me if it's possible to centre the screen with yoke adjustments? Don't have a remote.

[matt]

Could anyone tell me if it's possible to centre the screen with yoke adjustments? Don't have a remote.

No, the yoke doesn't work that way, it's a sync timing issue. Just get a remote - they're easy to find and cheap.

[realm]

I just picked up a little Sony Trinitron KV-9PT60. I know the RGB mod can be done on it, I found this post on reddit https://www.reddit.com/r/crtgaming/comm ... rst_image/

After doing some research I found the service manual https://drive.google.com/file/d/18wIjv3 ... sp=sharing and the datasheet on the jungle chip https://drive.google.com/file/d/1WOZcsD ... sp=sharing

The analog RGB input on the jungle chip isn't being used and are grounded at the moment. The person in the reddit post looks like they just removed those pins from being grounded, then injected RGB through 75R resistors and 4.7 uf caps into the jungle chip. in an update post he shows he upgraded to 500R trim pots and caps to 220uf.

Has anyone here done a mod on this little Sony?