TV RGB mod thread

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Osirus
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Re: TV RGB mod thread

Post by Osirus »

As I remember, the DPDT "went in" where JR1801 was. When OFF, the switch should connect the circuit as though JR1801 was still there, connecting the blanking from the micom to the jungle. When ON, it should connect 2.5V to the jungle via CN1802.
xer0510
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Joined: Fri Jan 10, 2014 6:29 am

Re: TV RGB mod thread

Post by xer0510 »

welp have it all wired up but it wont get past stand by :(

is there a spot on the mobo i can short to get past stand by?
Dial0
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Joined: Mon Jul 12, 2021 10:15 pm

Re: TV RGB mod thread

Post by Dial0 »

Has anyone done RGB insertion on the Philips UOCIII Jungle chips? TDA11000H/H1 to TDA12079H/H1 Series?

I got an old sony WEGA TV that has one of these chips and it has a RGB insertion, however it looks like it has a lot of customization in the software.

I found a bunch of datasheets and schematics, but keen to know if its been done before?

Here is the schematic for the TV I have, however only 2 composite inputs are actually populated, the RGB insertion has nothing connected to it.
https://ufile.io/9mlzuhwe
This is the datasheet for the jungle chip
https://ufile.io/5k5nw1uo
and this is a schematic for a tv using the RGB interface for scart
https://ufile.io/yrp223fb

Sorry about the weird file host, but not sure the best way to share these files.
ashhhhh
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Joined: Thu Jul 15, 2021 10:35 am

Re: TV RGB mod thread

Post by ashhhhh »

This is an awesome thread.

I was wondering if someone could elaborate on the mod for the cxa2139s shown by Syntax (the man himself if possible!) on page 35?
Im trying to mod a Sony KV-XF29M35 that used that jungle chip.

The solution shown looks elegant but I cant make out the detail. (or at least im too dense to make it out :lol: )

Any assistance would be much appreciated. (including alternate solutions, if better ones exist)
snappleman
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Joined: Tue Aug 22, 2017 9:05 pm

Re: TV RGB mod thread

Post by snappleman »

I'm getting around to finishing this mod on m JVC C-20210, it has a TA1242N jungle chip and I opted to do the switch method because all the resistors on the RGB lines from the micom are the tiniest little surface mount things I've ever seen.

Everything works nearly perfectly and I do get a great RGB image but I can't get the white balance quite right. With 75ohm termination it's too dark and dull, the best value I found is 200ohm for what looks like a nearly perfect picture except it's very hard to get a good screen balance. If the flyback is set to have perfect black level then it's just a tiny bit too dark.

I'm also making an RGB amp for one of my MVS boards and everything I read says to put 75ohm resistors in line with the output from the THS7316 to match the termination on the TV input, but the TV input is 200ohm so I feel like I did that wrong?

Then I looked at the schematic more careful and noticed this:

Image

It looks like the input voltages for RGB are 4.5V? I plugged an MVS board in with 75ohm termination and the levels seem spot on just like my arcade monitor, does this mean this jungle needs TTL level signals to look right? I do have Tim Worthington's SCART to Jamma that I use for an arcade setup, but before I try that I'd like to confirm it would be a smart choice for my consoles. The RGB input is going directly into the jungle, aside from the surface mount parts that are clustered around the pins of the micom it's a clean run straight to the jungle via some jumpers that I removed and soldered DIP connectors on to going to a switch.
ashhhhh
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Re: TV RGB mod thread

Post by ashhhhh »

Anyone able to assist with a Samsung SCT12B chassis mod?
This is in a Samsung "TV-6861" but that doesn't mean much it seems and I can't locate a service manual.

It uses the TDA8375.

What I find interesting is it seems to have a straight RGB input, perhaps because there is a TV that uses this chassis and has SCART. (Mine doesn't)
I've tried simply patching into those lines but no joy, they seem to run direct to the jungle via some 0.1uf caps but I'm not sure what else might be required to do that.

Aside from that it has the usual osd lines.

Anyway, I'm lost and confused as to the best way to go here, any help much appreciated.
https://photos.app.goo.gl/UYJEonvw6BjAVuRV7
MarkOZLAD
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Re: TV RGB mod thread

Post by MarkOZLAD »

ashhhhh wrote:Anyone able to assist with a Samsung SCT12B chassis mod?
This is in a Samsung "TV-6861" but that doesn't mean much it seems and I can't locate a service manual.

It uses the TDA8375.

What I find interesting is it seems to have a straight RGB input, perhaps because there is a TV that uses this chassis and has SCART. (Mine doesn't)
I've tried simply patching into those lines but no joy, they seem to run direct to the jungle via some 0.1uf caps but I'm not sure what else might be required to do that.

Aside from that it has the usual osd lines.

Anyway, I'm lost and confused as to the best way to go here, any help much appreciated.
https://photos.app.goo.gl/UYJEonvw6BjAVuRV7
Keep looking at the schematic, there's more.
___________________________________________________
MarkOZLAD
OSD/External RGB Mux Diagram
OSD/External RGB Mux Resistor Value Table 0.7Vp-p : 0.5Vp-p

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

Post by ashhhhh »

MarkOZLAD wrote: Keep looking at the schematic, there's more.
Any hints here? :wink:
As best as I can tell this is going to be virtually the same as the mod the "8 bit guy"used (with your assistance?) but I thought the inputs marked "21p" (ie. SCART) might be an easier route.

I've just got no experience with the mod yet, once I do one and see the approach and thinking behind that it will help massively.
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Osirus
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Re: TV RGB mod thread

Post by Osirus »

You need to apply a voltage to RGB Fast Blanking (pin 26). Probably around 3V.
MarkOZLAD
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Re: TV RGB mod thread

Post by MarkOZLAD »

ashhhhh wrote:
MarkOZLAD wrote: Keep looking at the schematic, there's more.
Any hints here? :wink:
As best as I can tell this is going to be virtually the same as the mod the "8 bit guy"used (with your assistance?) but I thought the inputs marked "21p" (ie. SCART) might be an easier route.

I've just got no experience with the mod yet, once I do one and see the approach and thinking behind that it will help massively.

Image
___________________________________________________
MarkOZLAD
OSD/External RGB Mux Diagram
OSD/External RGB Mux Resistor Value Table 0.7Vp-p : 0.5Vp-p

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

Post by MarkOZLAD »

Dial0 wrote:Has anyone done RGB insertion on the Philips UOCIII Jungle chips? TDA11000H/H1 to TDA12079H/H1 Series?

I got an old sony WEGA TV that has one of these chips and it has a RGB insertion, however it looks like it has a lot of customization in the software.

I found a bunch of datasheets and schematics, but keen to know if its been done before?

Here is the schematic for the TV I have, however only 2 composite inputs are actually populated, the RGB insertion has nothing connected to it.
https://ufile.io/9mlzuhwe
This is the datasheet for the jungle chip
https://ufile.io/5k5nw1uo
and this is a schematic for a tv using the RGB interface for scart
https://ufile.io/yrp223fb

Sorry about the weird file host, but not sure the best way to share these files.
I have personally tried and helped three other people try and mod these chips to no avail. I believe it is because the RGB inputs are locked out in software. If the TV has the appropriate service menu options to allow RGB it may be possible. It might be possible instead to do a YPbPr mod.
___________________________________________________
MarkOZLAD
OSD/External RGB Mux Diagram
OSD/External RGB Mux Resistor Value Table 0.7Vp-p : 0.5Vp-p

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

Post by MarkOZLAD »

ashhhhh wrote:
MarkOZLAD wrote: Keep looking at the schematic, there's more.
Any hints here? :wink:
As best as I can tell this is going to be virtually the same as the mod the "8 bit guy"used (with your assistance?) but I thought the inputs marked "21p" (ie. SCART) might be an easier route.

I've just got no experience with the mod yet, once I do one and see the approach and thinking behind that it will help massively.
I notice in the photo where you are pointing out the caps that there is an empty header that says R G B F/B. I'd be investigating that. Likely just need to put 75 ohm terminated RGB into that and a blankigng voltage (3V or less) into F/B.
___________________________________________________
MarkOZLAD
OSD/External RGB Mux Diagram
OSD/External RGB Mux Resistor Value Table 0.7Vp-p : 0.5Vp-p

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

Post by dlxmax »

Thanks to everyone who continues to contribute here!
Last edited by dlxmax on Tue Jul 27, 2021 7:37 am, edited 1 time in total.
ashhhhh
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Re: TV RGB mod thread

Post by ashhhhh »

MarkOZLAD wrote:
ashhhhh wrote:
MarkOZLAD wrote: Keep looking at the schematic, there's more.
Any hints here? :wink:
As best as I can tell this is going to be virtually the same as the mod the "8 bit guy"used (with your assistance?) but I thought the inputs marked "21p" (ie. SCART) might be an easier route.

I've just got no experience with the mod yet, once I do one and see the approach and thinking behind that it will help massively.
I notice in the photo where you are pointing out the caps that there is an empty header that says R G B F/B. I'd be investigating that. Likely just need to put 75 ohm terminated RGB into that and a blanking voltage (3V or less) into F/B.
Thanks Mark, I'm using a different header (nearer to the AV ports but also labelled rgb and has continuity with the one you identified) but we had the same thought.
My blanking voltage is 3.4 and seems to work. (It does blank and I can see the image, albeit flickering/unsynced)

I've got it wired up but have weird behaviour.

It clearly has a sync problem for starters, I've connected one of the composite ports to pin 20 on the SCART head. That should be sufficient yeah?
There's also no audio, again I've just wired the red/white inputs into the SCART head.
If I switch between inputs from av1/av2/tv I can hear the audio for half a second and then it seems to cut it.

Any of this sound familiar?
I can take some video if the description above isn't clear.
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Osirus
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Re: TV RGB mod thread

Post by Osirus »

Make sure the TV is set to whatever input you have composite sync connecte to.
ashhhhh
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Re: TV RGB mod thread

Post by ashhhhh »

Osirus wrote:Make sure the TV is set to whatever input you have composite sync connecte to.
I have, it makes no difference.
In fact, I see the same flickery image on ALL inputs including TV. (As well as no audio)
ashhhhh
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Joined: Thu Jul 15, 2021 10:35 am

Re: TV RGB mod thread

Post by ashhhhh »

Well, used AV2 instead of AV1 as the sync source and it's working!
Great stuff, thanks for your help guys.
luizlink64
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Joined: Fri Jun 11, 2021 5:00 pm

Re: TV RGB mod thread

Post by luizlink64 »

Hi, nice to meet you all. First of all, my name is Luiz, I am brazilian, i know the basics of soldering, got a simple digital multimeter and i'm familiar with discharging the tv tube. I am a software developer but I am not familiar nor have any kind of knowledge on eletronics.

Here is my goals and setup:

I'm looking for RGB crt tv mod so I can play Smash Bros Melee and a few other online fighting games, on my computer with 0 input lag. Instead of investing a lot of money on 240/360hz modern monitors, I still believe the good old CRT tvs are the best when input lag is a concern. Then, enjoy retrogaming on emulators, like Groovymame.

I'm researching and trying rgb mod on crt tvs for some months, but still didn't managed to get it right. My only success was a neckboard RGB mod on a LG Flatron TV, but i wasnt satisfied with the results. The image gets white-ish on dark scenes, to the point retrace lines are visible, but on bright scenes, the image gets very dark.

After the failed neckboard rgb mod, i got a brazilian 20 inch Toshiba CRT TV - exact model is TV2087FMS with the U11 Chassis. Image color, bright and contrast is great, geometry is okay, convergence is also okay. Only one visible defect, it has intense blooming - image shrinks on darker scenes , and expands a lot when there is a bright scene. I'll be glad if someone knows how to mitigate or fix it.

I do not plan to use it for arcades or consoles, just on PC.

my test PC Setup:
Windows 7
AMD Athlon 64 x2 5000+
AMD Radeon HD5450

Already installed EmuCRT Driver, and using the VGA Analog output with correct frequencies. I've succeeded to output PC image on the LG Flatron with neckboard rgb, using this cable - VGA to 5 BNC connectors (RGB, Hsync, Vsync).
EmuCRT Driver is configured to output CSync on VGA H-Sync pin.

But for now i'm planning to make an Female VGA port on the TV, then wire the VGA pins into the TV board. I think BNC connectors are too bulky.
I'm also planning to use the VGA 5v for fast blanking, instead of stealing 5v from the TV board.

___________________________________________________________________________________

Now onto the modding.

Still didn't managed to find the service manual, only the TV Toshiba U11 chassis schematics. Here is the download link for it.

https://www.electronica-pt.com/esquema/ ... no_html,1/


The controller IC of the schematic - tmp87ck38n is the same here on my TV Chassis. got the datasheet: https://pdf1.alldatasheet.com/datasheet ... CK38N.html
Image

Now the first problem is, the Jungle chip differs. The Jungle IC on TV U11 Chassis Schematic is Toshiba TB1238N, but the IC on my tv is a Toshiba 1275AN. I've noticed that this was already repaired in the past, since I've found a lot of bad soldering on the jungle Ic solder points. My guess is - probably the original jungle chip was dead and then whoever did the job, put this 1275AN .
Image

However, there are still other problems - I didn't found any datasheet of the TB1275AN jungle IC.
****Edit****

I think I've found a pin-compatible IC Datasheet that seems to share almost everything from the jungle chip ( TB1275AN) I have.
Datasheet for TB1254N, fully in english
https://www.electronica-pt.com/media/ku ... ASHEET.pdf
Image

***********

Then, another problem - All datasheet I found on the internet of the TB1238N seems to be different from the TV schematic and the actual chassis.

RGB section of internet TB1238N datasheet.
It seems to be - pin 13 is the Blank signal, then RGB on 14,15,16.
Image

Now the RGB Section of the U11 Chassis schematic.

Blank signal is supposed to be on pin 15, then RGB on 16,17,18.
Image

So far i've traced only the pin 15 on my TB1275AN, and it is indeed conected to pin 25 on the controller IC. There is just one SMD resistor between the controller and jungle ic, as it shows on the schematics.

Chassis Schematic
Image
controller ic schematic
Image


Can anyone help me on this rgb mod? I'm happy if someone could guide me with a basic mod with a switch to turn on/off the 5v on blanking.
Last edited by luizlink64 on Tue Jul 27, 2021 4:08 am, edited 3 times in total.
luizlink64
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Re: TV RGB mod thread

Post by luizlink64 »

After some eyeballing on the board traces, i've confirmed



controller ic Blanking -> 2.2k ohm SMD resistor -> jungle blanking
controller ic R, G, B -> 6.8k ohm SMD resistor -> 820 ohm SMD resistor to ground -> 0,47uf/100V electrolytic capacitor -> jungle rgb

schematics says 0,47/50v caps, but the ones on the board are 100v.
Akuji
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Re: TV RGB mod thread

Post by Akuji »

Hello everyone, I got a question.

I recently modded a Sharp 13K-M100 for RGB. However, I'm now getting some retrace lines towards the top of my screen after the mod. As the TV powers on fresh it also takes a bit for those lines to show up, and as time passes the OSD starts to bleed horizontally in RGB mode as well. My biggest hunch is that it has to do with a bad capacitor that handles vertical phase/blanking, since adjusting vertical phase in the service menu adds a new line every time I increase it by one, but I can't decrease it past 0 to remove every line. That's just a guess though (I don't know this stuff really, I just Googled a lot), it's possible that maybe the way I modded the CRT could have also caused this, since this wasn't a problem before I modded it. I used the same exact method done by a previous modder from this thread, just using a SCART port instead of BNC.

Here's my drawing of what I did, using Mark's original drawing from his signature.
Spoiler
Image
Here's some videos of it:
https://files.catbox.moe/nk5lss.webm
https://files.catbox.moe/8y99z6.webm (My camera is doing that scrolling shimmer thing, not the tv)

Here's the manual:
https://files.catbox.moe/ea2ckj.pdf

I was wondering if anyone could tell me what specific caps I should check that could be the cause of this. I currently don't have the TV on me for a while so before I do I'd like to know what would be the best thing to tackle first.
luizlink64
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Re: TV RGB mod thread

Post by luizlink64 »

I've removed the caps from RGB input and got the RGB wires direct into the jungle chip. I got both sync and some colors when using the OSD, however, when i put 5v on pin 15 of the jungle chip, the entire screen turns black, it bypasses the blue screen and noise on normal channels.
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matt
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Re: TV RGB mod thread

Post by matt »

Akuji wrote:I recently modded a Sharp 13K-M100 for RGB. However, I'm now getting some retrace lines towards the top of my screen after the mod.
This is probably not due to the mod. What you're describing sounds like vertical foldover, which is cause by a bad pump-up capacitor in the vertical deflection circuit. It is a very common problem. On your TV it is C508 (100uF/35v). Make sure to replace it with a low ESR/high ripple current cap or else the problem will come back sooner or later.
Akuji
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Re: TV RGB mod thread

Post by Akuji »

matt wrote:
Akuji wrote:I recently modded a Sharp 13K-M100 for RGB. However, I'm now getting some retrace lines towards the top of my screen after the mod.
This is probably not due to the mod. What you're describing sounds like vertical foldover, which is cause by a bad pump-up capacitor in the vertical deflection circuit. It is a very common problem. On your TV it is C508 (100uF/35v). Make sure to replace it with a low ESR/high ripple current cap or else the problem will come back sooner or later.
Thanks, I will order one and replace it soon.
coredump
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Re: TV RGB mod thread

Post by coredump »

Hello, long time lurker here.

I am trying to get a Sony 27V66 (that is the same chassis and everything as 27V42 but with better speakers) modded and I am very close, but no game. It uses a CXA2133S Jungle IC, that I couldn't find the datasheet, but apparently the CXA2061S is close enough.
This Jungle has an extra, not connected, RGB input on pins 26-28, and a YS pin to select that input on 25.I connected stuff there and sent some signal, but the input doesn't seem to be enabled by default.

I did some digging and using an Arduino I was able to flip the i2c bits necessary, and I finally got it working, except that the image is waaaaaay to the left, even after going into the service manual and changing the HPOS all the way to 0. There's also some interference on the top of the image that kinda flickers when I poke the wire that is connecting the 3.3V to pin 25 (anything over 0.7 and under 7.5 on that pin is 'enable input'). For the technically inclined, it's the last bit on address 0xA that needs to be flipped to 0 (so I just send a 0xC0 to it).

Does anyone have any experience with this, tips on what to try, or should I just OSD Mux this tv and be done? I am attaching an image of what I am dealing with. Those are running on a MiSTer using the SNES version of 240p test suite.

Screen image:
Spoiler
Image
RGB input info from the CXA2061S datasheet
Spoiler
Image
RGB SEL i2c address
Spoiler
Image
MarkOZLAD
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Re: TV RGB mod thread

Post by MarkOZLAD »

luizlink64 wrote:I've removed the caps from RGB input and got the RGB wires direct into the jungle chip. I got both sync and some colors when using the OSD, however, when i put 5v on pin 15 of the jungle chip, the entire screen turns black, it bypasses the blue screen and noise on normal channels.
Why did you remove the caps?
___________________________________________________
MarkOZLAD
OSD/External RGB Mux Diagram
OSD/External RGB Mux Resistor Value Table 0.7Vp-p : 0.5Vp-p

"Imagine toggle switch OSD modding a TV in 2019" - maxtherabbit
luizlink64
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Re: TV RGB mod thread

Post by luizlink64 »

MarkOZLAD wrote:
luizlink64 wrote:I've removed the caps from RGB input and got the RGB wires direct into the jungle chip. I got both sync and some colors when using the OSD, however, when i put 5v on pin 15 of the jungle chip, the entire screen turns black, it bypasses the blue screen and noise on normal channels.
Why did you remove the caps?
Hi Mark! Thanks for your reply!

Reason I removed the caps was just for quick testing, I've already put the caps back on the board. Still stuck on black screen when applying 5v to blanking line. Since my switch isn't double throw, perhaps 5v is going back into the microcontroller and messing with it?

Edit:

I think I've found a pin-compatible IC Datasheet that seems to share almost everything from the jungle chip ( TB1275AN) I have.
TB1254N

https://www.electronica-pt.com/media/ku ... ASHEET.pdf
DemoNight
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Re: TV RGB mod thread

Post by DemoNight »

MarkOZLAD wrote:
rage8885 wrote:I'm hoping someone can give me some feedback / help on an RGB mod I'm attempting. I've got a Sony Trinitron KV-27V20 (AA-2 chassis) that I was able to pick up for free locally - if I screw it up I won't lose any sleep, but I'd love to get this right the first time. From reading through this post and seeing how others have modded similar TV models, I've put together a diagram of what I "think" I need to do:
Spoiler
Image
The OSD (IC001) RGB and BLK lines need to be cut and redirected into aa 4PDT switch. The lines coming from the Jungle (IC351) RGB and YS also need to be redirected into the 4PDT with the RGB lines having 0.1uF capactiors in line. Finally, I'm adding 3 BNC connectors (RGB) with negative attached to ground, and positive attached to the 4PDT with 75 ohm resistors inline and also attached to ground. I'm also going to feed the 5V standby into the 4PDT switch.
Spoiler
Image
When the switch is "on" the RGB from the BNC connectors and the 5v standby will be hooked up to the Jungle RGB and YS.

When the switch is "off", the OSD RGB and BLK will be hooked up to the Jungle RGB and YS instead.

I took the TV apart and pulled out the A board and tracked down the components:
Spoiler
Image (front)
Image (back)
At this point I'm trying to figure out / understand the best place to actually do the mod. My soldering skills are fairly basic and while I can solder small-ish wires without any issues, I've yet to attempt soldering anything surface mount. I've identified two areas where the mod can potentially be done (A and B on the images).

The easier of the two looks like it would be "A" which is nearby the OSD (IC001) chip. There are 4 resistors on the top of the board that are nice and accessible - my thoughts are to remove the resistors and proceed with the mod using the holes on the board in place of the resistors. After removing these resistors I assume I need to keep them in the circuit / reattach them.

With that said, there is an area of the circuit between the OSD and Jungle that I'm not sure of the purpose (the purple question mark on the circuit diagram / back of the circuit board). It looks like there are a number of transistors for each line (RGB) that are attached to the 9V line. Does it matter what side of this area I do the mod?

The harder of the two is "B". I'll be honest, I'm not even sure how to attempt this mod here - the components all appear to be surface mount and possibly even under the Jungle (IC351) itself?

If I can't do "A", is there an easier way of modding this than attempting "B"? I can post the service manual / datasheet for the Jungle IC for this TV as well if that helps. The Jungle IC is a Sony CXA2025S.

https://imgur.com/a/LnylNEG (additional pics from the service manual / board)

This AA-2 chassis TV can also be OSD Mux modded easily. It's already been covered in the thread but here we go again.

This set has an unusual OSD RGB circuit because it converts RGBI to RGB through a series of transistors but that is ok, there is still a simple way to do it.

R1123, R1128 and R133 are the OSD termination resistors that we want to target for the OSD mux. So we remove them.

They are 390 ohm resistors. Instead of using the OSD/External RGB muxing calculator to work out our mux resistors we will just cheat and subtract 75 from 390 to get something close. 390 - 75 = 315. Next standard resistor size is 330 ohms.

So we want to inject our 75 ohm terminated RGB into 330 ohm resistors and then into circuit somewhere between R1121 (Red) , R1126 (Green) , R131 (Blue) and R1355 (Red), R1356 (green) and R1357 (blue). IIRC correctly there are jumpers in there but it's been a while so i may be mistaken. The ungrounded pads left by removing R1123, R1128 and R133 are an obvious spot but may not be suitable.

For a very simple blanking circuit try taking a 5V line to the input of single point switch, then connect the output of the switch to a 470 ohm resistor and solder it onto the leg of L003 that is closest to IC001. Quick and dirty but should work fine.
Hey, sorry to bother you. About to attempt to RGB mod two AA-2 chassis Sonys (KV-32V36 and a KV-32S40). Gonna be upfront and say my electrical engineering knowledge is cursory at best so I apologize for my stupid questions. But, shouldn't i need a diode in circuit to keep the RGB voltage from back feeding into the MICON chip? Second question, could you clarify your blanking circuit? I was under the impression I needed to apply 5v to leg 16 of IC351 (YM leg of the jungle chip). In this post your saying to apply to take 5v, add a 470ohm resistor, then apply that to a leg of the L003, I don't understand this at all, I also don't see any chips called L003 on the diagram i'm looking at. Thanks for any help you can provide.
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Osirus
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Re: TV RGB mod thread

Post by Osirus »

DemoNight wrote: Hey, sorry to bother you. About to attempt to RGB mod two AA-2 chassis Sonys (KV-32V36 and a KV-32S40). Gonna be upfront and say my electrical engineering knowledge is cursory at best so I apologize for my stupid questions. But, shouldn't i need a diode in circuit to keep the RGB voltage from back feeding into the MICON chip? Second question, could you clarify your blanking circuit? I was under the impression I needed to apply 5v to leg 16 of IC351 (YM leg of the jungle chip). In this post your saying to apply to take 5v, add a 470ohm resistor, then apply that to a leg of the L003, I don't understand this at all, I also don't see any chips called L003 on the diagram i'm looking at. Thanks for any help you can provide.
The diodes can be used but aren't necessary. The OSD outputs on the microcontroller aren't harmed by having a voltage on them. Whether or not you use them determines the values of your resistors since they have their own voltage drop across them.

L003 is an inductor, not an IC. He means to use the pad on L003 to apply your own blanking voltage as that's the same point in the circuit that the microcontroller applies the normal blanking voltage.
DemoNight
Posts: 33
Joined: Sat Mar 24, 2018 2:53 am

Re: TV RGB mod thread

Post by DemoNight »

Osirus wrote:
DemoNight wrote: Hey, sorry to bother you. About to attempt to RGB mod two AA-2 chassis Sonys (KV-32V36 and a KV-32S40). Gonna be upfront and say my electrical engineering knowledge is cursory at best so I apologize for my stupid questions. But, shouldn't i need a diode in circuit to keep the RGB voltage from back feeding into the MICON chip? Second question, could you clarify your blanking circuit? I was under the impression I needed to apply 5v to leg 16 of IC351 (YM leg of the jungle chip). In this post your saying to apply to take 5v, add a 470ohm resistor, then apply that to a leg of the L003, I don't understand this at all, I also don't see any chips called L003 on the diagram i'm looking at. Thanks for any help you can provide.
The diodes can be used but aren't necessary. The OSD outputs on the microcontroller aren't harmed by having a voltage on them. Whether or not you use them determines the values of your resistors since they have their own voltage drop across them.

L003 is an inductor, not an IC. He means to use the pad on L003 to apply your own blanking voltage as that's the same point in the circuit that the microcontroller applies the normal blanking voltage.
Thanks for the reply, i'll leave the diodes out since the math is already done for me to not have them. Though, and this is more of a theory question then a question for this project, but I don't understand how a diode will effect resistor values in this case. If I go both resistors, then a diode on the cricut back to the microcontroller how does that affects the resistance on the circuit going to the jungle?

Anyways, my only other question is for sync, do I need to add resistors to that? I plan to solder onto the back side of the composite input to a female scart plug that i'm going to mount in the case. Actually, two more questions come to mind if that's ok. First, I read a few people say the resistors on the RGB input should be resistors to ground, I won't even bother to ask why that makes a difference but with this version of the mod I should ground all 3 signal wires with a 75ohm resistor for each (and to be super clear we are talking the grounds on the scart plug, i'm planning to ground the scart plug itself to the same composite ground), do I still need that 0.01 cap in that circuit I see other people use? Then have the signal wires run to that 330ohm resistor then bring the output of that into the Micro to Jungle chip circuit, do I have that right?

And for that L003 inductor, i'm going to apply 5v to the input side of that inductor with a 470ohm to blank the screen, is that right?
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Osirus
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Re: TV RGB mod thread

Post by Osirus »

DemoNight wrote:
Thanks for the reply, i'll leave the diodes out since the math is already done for me to not have them. Though, and this is more of a theory question then a question for this project, but I don't understand how a diode will effect resistor values in this case. If I go both resistors, then a diode on the cricut back to the microcontroller how does that affects the resistance on the circuit going to the jungle?

Anyways, my only other question is for sync, do I need to add resistors to that? I plan to solder onto the back side of the composite input to a female scart plug that i'm going to mount in the case. Actually, two more questions come to mind if that's ok. First, I read a few people say the resistors on the RGB input should be resistors to ground, I won't even bother to ask why that makes a difference but with this version of the mod I should ground all 3 signal wires with a 75ohm resistor for each (and to be super clear we are talking the grounds on the scart plug, i'm planning to ground the scart plug itself to the same composite ground), do I still need that 0.01 cap in that circuit I see other people use? Then have the signal wires run to that 330ohm resistor then bring the output of that into the Micro to Jungle chip circuit, do I have that right?

And for that L003 inductor, i'm going to apply 5v to the input side of that inductor with a 470ohm to blank the screen, is that right?
The sync input you apply your sync to should already have its own 750 ohm termination if you apply your sync to the composite input. No need for any resistors there.

The RGB inputs you add need to have 75 ohm resistors to ground. That's standard for analog video signals. It will match the output impedance of the devices you connect to the tv. If you look at the composite, s-video, or component inputs that the tv already has they will also measure 75ohm to ground.

What you said about the 470ohm resistor to the L003 inductor sounds right, without looking.
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