TV RGB mod thread

[Syntax]

I had the most backward jungle IC yesterday, ended up throwing the set out.
CENTREX
Jungle SANYO LA76810A

R - 14
G - 15
B - 16
Blanking - 17 (3v)

PDF schematic has an odd setup for RGB input, wants the signal clamped THEN terminated with a 1k resistor.
The jungle will not accept any clamped signal though, 3 different values and 3 different types of caps used, none will get signal through.
Looks at OSD and its just going through a 4.7k resistor on each color line, no terminations or caps...
Terminated with 75ohm resistors the picture is too dark..
So I put a 1k pot on the tail end of my 75ohm resistors which should of in theory made the picture darker as I increase the termination resistance.
As I increase the resistance it gets BRIGHTER!

I removed the termination resistors and put a triple gang 1k pot in its place. Its effectively a brightness knob now.
Connecting it directly to the jungle results in a black screen that you can turn up to white.
Since when do direct terminations with no signal feed make a white screen??
The Jungles internal channels were blue pink and yellow when you terminate 2 so you can see 1.
Internal color channels... WTF
Its like the whole Peak to Peak reading of the color channels is inverted logic or something.

I threw the set away though because I couldn't get definition in the RGB picture, The black levels were all whack I think.
That and the 4pdt and scart connectors worth more.
Literally the most backwards Jungle ive ever worked on, Centrex must of wired so wrong but I didn't have the time to check it further.
I did get RGB out of it so ill call it a draw.

[buttersoft]

I've got a Sanyo that does something similar - when fed sync, blanking and red only, no G or B, the screen comes up as a pale aqua colour, very washed out. Adding G and B in as well makes a normal, clear, colour-correct picture. Without caps and terminations you pretty much get nothing. No idea what's happening there, but i don't think i've crossed any wires.

Those video wall monitors were the ones from the surf-clothing-shop-looking add on gumtree? The old Barco ones? Let us now how they go, the similar units by Hantarex tend to have the TVL of a consumer set. Not that there's anything wrong with that...

[MarkOZLAD]

Syntax, you might be able to help with this one.

Helping another Brazillian chap do a mod.

He has a Phillips 21PT534A/78R. It has a TDA 8841 Jungle. It's another one of those that completely blanks the RGB lines at 4V, same as for Marcos.

Seeing really weird behaviour. Have connected the blanking pin to a 5V source (in fact we've tried two, the 5V regulator and the Fac Serv line for Serial Port) via a 10K pot. We can get blanking to happen but it only lasts for a short while and then the blanking stops again. TV Returns to showing only sync. As my Brazillian friend put it, it is like the blanking pin is hungry! Repeated turns of the potentiometer result in the same thing, blanking and then blanking stops after a short while.

I am a complete novice when it comes to the blanking. I've been lucky that the TVs I've modded have been dead simple to get blanking, just 5V or 5V with a pot/resistor. this one has me confounded. Any help would be appreciated.

Cheers,

Mark

[MarkOZLAD]

The NES RGB problem shown in that picture is a result of the image being shifted far left. As a result, the overscan border color (blue, in the case of the Super Mario Bros sky) is being used as the clamping level for black. The TV subtracts the black level sample from the rest of the line, so if your black level has image data there you'll get strange color subtraction effects in the line. You need to use the service menu to shift the image right, or change the clamping delay. If you have other inputs to try like S-video or Component, try using those for sync.

You were right, it was from the overscan area being used as black level. I moved it over to S-video and now the NESRGB is perfect. Thanks!

Glad you got it sorted, looks like a very successful mod.

Did you create an adaptor chord to send the sync into the S-Video port or did you wire the sync line internally to a Y pin?

[Syntax]

Syntax, you might be able to help with this one.

Helping another Brazillian chap do a mod.

He has a Phillips 21PT534A/78R. It has a TDA 8841 Jungle. It's another one of those that completely blanks the RGB lines at 4V, same as for Marcos.

Seeing really weird behaviour. Have connected the blanking pin to a 5V source (in fact we've tried two, the 5V regulator and the Fac Serv line for Serial Port) via a 10K pot. We can get blanking to happen but it only lasts for a short while and then the blanking stops again. TV Returns to showing only sync. As my Brazillian friend put it, it is like the blanking pin is hungry! Repeated turns of the potentiometer result in the same thing, blanking and then blanking stops after a short while.

I am a complete novice when it comes to the blanking. I've been lucky that the TVs I've modded have been dead simple to get blanking, just 5V or 5V with a pot/resistor. this one has me confounded. Any help would be appreciated.

Cheers,

Mark

Page 15

By means of the IE1 bit the insertion blanking can be switched on or off. Via the IN1 bit it can be read whether the insertion pin has a high level or not.

FAST BLANKING, PIN 26 (38 AND 44 FOR TDA 885X)
S.3.1 input voltage no data insertion −−0.4 V S.3.2 data insertion 0.9 0.6 − V


Did you try wire a 10k pot with 5v one side and ground the other side with blanking pin in the middle?

When in doubt get out the multimeter and trace out the OSD blanking path, make note of the components and if it has a termination resistor there is a good chane you will need to wire the pot like that.

[MarkOZLAD]

Syntax, you might be able to help with this one.

Helping another Brazillian chap do a mod.

He has a Phillips 21PT534A/78R. It has a TDA 8841 Jungle. It's another one of those that completely blanks the RGB lines at 4V, same as for Marcos.

Seeing really weird behaviour. Have connected the blanking pin to a 5V source (in fact we've tried two, the 5V regulator and the Fac Serv line for Serial Port) via a 10K pot. We can get blanking to happen but it only lasts for a short while and then the blanking stops again. TV Returns to showing only sync. As my Brazillian friend put it, it is like the blanking pin is hungry! Repeated turns of the potentiometer result in the same thing, blanking and then blanking stops after a short while.

I am a complete novice when it comes to the blanking. I've been lucky that the TVs I've modded have been dead simple to get blanking, just 5V or 5V with a pot/resistor. this one has me confounded. Any help would be appreciated.

Cheers,

Mark

Page 15

By means of the IE1 bit the insertion blanking can be switched on or off. Via the IN1 bit it can be read whether the insertion pin has a high level or not.

FAST BLANKING, PIN 26 (38 AND 44 FOR TDA 885X)
S.3.1 input voltage no data insertion −−0.4 V S.3.2 data insertion 0.9 0.6 − V


Did you try wire a 10k pot with 5v one side and ground the other side with blanking pin in the middle?

No we haven't. We will try that next.

Thanks for the reply.

[MarkOZLAD]

When in doubt get out the multimeter and trace out the OSD blanking path, make note of the components and if it has a termination resistor there is a good chance you will need to wire the pot like that.

Now that is interesting. The schematic shows the OSD blanking being terminated to a 4.7KOhm resistor. Will follow up that lead.

Thanks again as always.

[nakedarthur]

The NES RGB problem shown in that picture is a result of the image being shifted far left. As a result, the overscan border color (blue, in the case of the Super Mario Bros sky) is being used as the clamping level for black. The TV subtracts the black level sample from the rest of the line, so if your black level has image data there you'll get strange color subtraction effects in the line. You need to use the service menu to shift the image right, or change the clamping delay. If you have other inputs to try like S-video or Component, try using those for sync.

You were right, it was from the overscan area being used as black level. I moved it over to S-video and now the NESRGB is perfect. Thanks!

Glad you got it sorted, looks like a very successful mod.

Did you create an adaptor chord to send the sync into the S-Video port or did you wire the sync line internally to a Y pin?

I used BNC jacks for this one, so what I ended up doing is removing the 4th jack for sync and modded my Monoprice VGA to BNC cable so the sync line ends with an S-video connector. Easy enough

[mikejmoffitt]

Can you check what type of tube is in your KV-27S42? I'm on the hunt for an M68KUZ10X and I have reason to believe it may have one.

[nakedarthur]

Can you check what type of tube is in your KV-27S42? I'm on the hunt for an M68KUZ10X and I have reason to believe it may have one.

That's the one in the PVM-2950Q right? I have one with a bad tube, and tried looking for one also haha The Service Manual lists the KV-27S42 as using a "CRT 29NX" or Sony Part number 8-733-873-05.

[FinalBaton]

I succesfully completed this mod on a Sharp 27sc260 tv. It already had component and it looked good with the retrotek RGB to component converter but I was curious to see what RGB looked like on the TV. There is a definite difference in color but I imagine I could've done some service menu tweaks to get the component colors looking close or even identical to RGB. Here's a few comparison pics.

Rgb on the top, Component on bottom. It looks like there's some jailbars there but that's just the camera.

Spoiler

cyborc, the picture is friggin stunning on your newly-modded Sharp set

Look at that luminance accuracy...
Look at those rich but super well-balanced colors...

Great job!

[cyborc]

cyborc, the picture is friggin stunning on your newly-modded Sharp set

Look at that luminance accuracy...
Look at those rich but super well-balanced colors...

Great job!

Thanks! I was pretty impressed by how it turned out too.
I feel like Sharp CRTs tend to get lost in the crowd when people talk about consumer CRTs. They are the real deal!

[mikejmoffitt]

Can you check what type of tube is in your KV-27S42? I'm on the hunt for an M68KUZ10X and I have reason to believe it may have one.

That's the one in the PVM-2950Q right? I have one with a bad tube, and tried looking for one also haha The Service Manual lists the KV-27S42 as using a "CRT 29NX" or Sony Part number 8-733-873-05.

Yep, I've got a PVM-2950Q that looks like it's been dropped. After repairing the cracked A-board I powered it on and found that it works, except the purity is screwy in the corners. It's possible that the deguass coil just isn't firing since I have no evidence that it is.

It looks like you can take a tube from the KV-27XBR35 but that's all I can find. I got a KV-27V42 to harvest the tube but it has an A68****** tube in it. The socket is incompatible, otherwise I would have tried to make it work!

[nakedarthur]

Can you check what type of tube is in your KV-27S42? I'm on the hunt for an M68KUZ10X and I have reason to believe it may have one.

That's the one in the PVM-2950Q right? I have one with a bad tube, and tried looking for one also haha The Service Manual lists the KV-27S42 as using a "CRT 29NX" or Sony Part number 8-733-873-05.

Yep, I've got a PVM-2950Q that looks like it's been dropped. After repairing the cracked A-board I powered it on and found that it works, except the aperture grille has permanently ruined purity.

It looks like you can take a tube from the KV-27XBR35 but that's all I can find. I got a KV-27V42 to harvest the tube but it has an A68****** tube in it. The socket is incompatible, otherwise I would have tried to make it work!

Man that sucks! I also saw the KVS-29SN1 apparently has it too, but I've never seen one before. Maybe its not a North American set? The tech that did my RGB mod recommended calling Video Display as that's where he used to get his replacement tubes, but they said they haven't had any for a long time. Seems to be about impossible to find now unfortunately. Please let me know if you ever run into a cache of them

[Syntax]

@mikejmoffitt Man you have a keen eye.
Id have to laugh if the tv my brother threw out because it only took composite was actually a PVM tube.

Understand I'm in no rush to remove the back of that set as the mod is done, but I will anyway.
Ill have to start taking notes for you guys hey

[Syntax]

Can you check what type of tube is in your KV-27S42? I'm on the hunt for an M68KUZ10X and I have reason to believe it may have one.

M68KZT71X

[mikejmoffitt]

Wow! That may be compatible. The M68 at the start indicates it is from the pro series, not the consumer A series. I will have to try to track down a 27S42.

[BobWoggle]

Ended up getting another tv, this one I know for a fact I can do. It's a sony kv27s10, its manual is here, along with several others'.

Now because the ccd is the one feeding analog rgb and sync into the jungle instead of the osd, I should be able to pop out the ccd chip, stick my new signals in where its output was, and everything'll be fine just like that, right?

I'm still not sure if I'm oversimplifying all this in my head because I'm too dumb to get it, or if it really is such a basic hack.

[Syntax]

Ccd probably has 470ohm termination resistors and tiny clamping caps. Always best to check the original path.

[MarkOZLAD]

Ended up getting another tv, this one I know for a fact I can do. It's a sony kv27s10, its manual is here, along with several others'.

Now because the ccd is the one feeding analog rgb and sync into the jungle instead of the osd, I should be able to pop out the ccd chip, stick my new signals in where its output was, and everything'll be fine just like that because the jungle has some sorta automatic rgb switching on the lines the ccd uses, yeah?

I'm still not sure if I'm oversimplifying all this in my head because I'm too dumb to get it, or if it really is such a basic hack.

If it's anything like Australian Teletext models you can attach 75ohm terminated RGB lines directly to the pins of the CCD under the chassis and also connect the 5V blanking there too.

Bare in mind that I have NOT thoroughly researched your set.

[BobWoggle]

@Syntax I would have figured the schematics would show that, no?

[Syntax]

Probably, but who trusts that, easy to flip the screen and just take a look at the path, sometimes they have all types of stuff connected.

Like Markoz said our teletext units should pretty much be like CCD. And most teletext hacks i've done have 400 something ohm termination resistors that need replacing.

75ohm SMD resistors and 100n caps would be handy

[mikejmoffitt]

Just going to put my idea to rest and then allow the thread to continue - for any poor soul searching for a M68KUZ10X tube replacement, the KV-27S42 and KV-27V42 are not suitable replacements.. The neck pinout is different and that's enough for me to lose interest. Neither have H-STAT adjustments so that'll really fuck with things if it's missing (probably).

The KV-27XBR35 should actually have the correct tube, so if I ever find one of those I'll jump for joy.

-------

On another note, I've got a KV-27V42 in excellent condition, so I'll probably go through the work of modding that and selling it in order to make up for the stupid sunk costs of this lemon PVM-2950Q.

[Syntax]

@Syntax I would have figured the schematics would show that, no?

KV-AR29M31
Teletext module with no real info on the CXA jungle ic.

Teletext module




Blanking is YS/YM but I checked the teletext blanking line and it had a termination resistor and 1k current limiting one so I left them there and just hoped for 5v injection.

Removed the 470ohm terminations and 10n caps and replaced with 75ohm and 100n


Stole the teletext units plug and wired to that, wired sync and sound to the dvd channel (luma)



Hacked a hole in the back and fit the scart plug, put the case back on minus 1 screw and crossed my fingers. First set put back together without testing.


Now on to the Quintrix..

[MarkOZLAD]

@Syntax I would have figured the schematics would show that, no?

KV-AR29M31
Teletext module with no real info on the CXA jungle ic.

Teletext module




Blanking is YS/YM but I checked the teletext blanking line and it had a termination resistor and 1k current limiting one so I left them there and just hoped for 5v injection.

Removed the 470ohm terminations and 10n caps and replaced with 75ohm and 100n


Stole the teletext units plug and wired to that, wired sync and sound to the dvd channel (luma)



Hacked a hole in the back and fit the scart plug, put the case back on minus 1 screw and crossed my fingers. First set put back together without testing.


Now on to the Qunitrix..

Is that a BG-3R chassis?

[Syntax]

Service manual that was the only thing with any info says it is yes.

Actually a really nice picture. But too bright. Will probably put higher ohm terminations in because I loose the menu at 10% brightness.

[MarkOZLAD]

Service manual that was the only thing with any info says it is yes.

Actually a really nice picture. But too bright. Will probably put higher ohm terminations in because I loose the menu at 10% brightness.

You did it in a lot more complicated way than I do a BG-3R. It is one you could've just soldered 75ohm terminated lines onto the pins of the teletext board where it is inserted in the chassis.

Anyway, you got the result.

I too noted the brightness issue with this model.

On a side note, you should be able to get it to blank using the teletext button.

[MarkOZLAD]

Syntax, you might be able to help with this one.

Helping another Brazillian chap do a mod.

He has a Phillips 21PT534A/78R. It has a TDA 8841 Jungle. It's another one of those that completely blanks the RGB lines at 4V, same as for Marcos.

Seeing really weird behaviour. Have connected the blanking pin to a 5V source (in fact we've tried two, the 5V regulator and the Fac Serv line for Serial Port) via a 10K pot. We can get blanking to happen but it only lasts for a short while and then the blanking stops again. TV Returns to showing only sync. As my Brazillian friend put it, it is like the blanking pin is hungry! Repeated turns of the potentiometer result in the same thing, blanking and then blanking stops after a short while.

I am a complete novice when it comes to the blanking. I've been lucky that the TVs I've modded have been dead simple to get blanking, just 5V or 5V with a pot/resistor. this one has me confounded. Any help would be appreciated.

Cheers,

Mark

Quick follow up on this one. The issue seems to have been caused by a faulty component somewhere in the chain. Still working it out, possibly a faulty pot.

It's difficult to mod a TV from half a world away through an intermediary. Fun though!

In the end, in order to get the blanking working I got them to install a AA battery. Negative to ground and positive to the blanking pin and voila, problem solved! (Blanking voltage is between 0.9V and 3.0V).

Will now try to determine what was wrong with initial setup.

[Syntax]

Service manual that was the only thing with any info says it is yes.

Actually a really nice picture. But too bright. Will probably put higher ohm terminations in because I loose the menu at 10% brightness.

You did it in a lot more complicated way than I do a BG-3R. It is one you could've just soldered 75ohm terminated lines onto the pins of the teletext board where it is inserted in the chassis.

Anyway, you got the result.

I too noted the brightness issue with this model.

On a side note, you should be able to get it to blank using the teletext button.

Every Teletext unit ive worked on has had 470ohm termination resistors on the rgb line, if your adding 75 ohm ones to that your terminating by around 270 ohm. (add the resistor values and half it)
I have a feeling that these units want 470 ohm so I'm going to put them back and see what happens.

I know you can use teletext button to blank but who wants to go find a remote? I always blank the way scart should, via the console 5v line.

[MarkOZLAD]

Service manual that was the only thing with any info says it is yes.

Actually a really nice picture. But too bright. Will probably put higher ohm terminations in because I loose the menu at 10% brightness.

You did it in a lot more complicated way than I do a BG-3R. It is one you could've just soldered 75ohm terminated lines onto the pins of the teletext board where it is inserted in the chassis.

Anyway, you got the result.

I too noted the brightness issue with this model.

On a side note, you should be able to get it to blank using the teletext button.

Every Teletext unit ive worked on has had 470ohm termination resistors on the rgb line, if your adding 75 ohm ones to that your terminating by around 270 ohm. (add the resistor values and half it)
I have a feeling that these units want 470 ohm so I'm going to put them back and see what happens.

I know you can use teletext button to blank but who wants to go find a remote? I always blank the way scart should, via the console 5v line.

My mods are working well but I'd be interested in your results. Mostly the teletext card is missing anyway and I use the empty port.

The note about the teletext blanking the screen was just meant to be a curious aside. I just install switches, take away the variables.