TV RGB mod thread

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MarkOZLAD
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Re: TV RGB mod thread

Post by MarkOZLAD »

cargo wrote:Thanks for the reply MarkOZLAD. I didn't do the mux approach because it looked too complicated for me. I would have needed a lot of help and didn't want to impose. I could still try it though.
I reviewed your design and it looks fine. The only thing I can think is that you've messed up in the implementation somehow. Left a blob of solder somewhere or something has a bad connection.

The Red showing is a great sign. Get your multimeter out and take measurements of continuity and resistance to ground on places on the red circuit and then do the same on green and blue and try look for differences.

As for the mux approach, I'd be more than willing to help. I already had notes on this exact chassis and as I'm not advanced enough in my electronics knowledge yet to know the exact method so I was going to recommend the use of a potentiometer to empirically determine the correct resistor size for the mux.

The mux approach is generally WAY EASIER than OSD Snip to implement. Simple, cleaner and better. Just need to study the chassis and the method a bit and think about where you inject your RGB. Note: I rarely use diodes anymore which makes it dead simple. It really isn't something to be scared of.
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Syntax
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Re: TV RGB mod thread

Post by Syntax »

Theres 2 ways to tackle the "mix" method Mark and I use.

If you don't care for figuring out values or using stock traces then you can pretty safely build a board that will turn osd 5vpp signal into .7vpp and mixes it and rgb into the jungle.

It's more parts but the same for every set, youd just isolate osd and jungle rgb pins and connect it all up.
Even if the Jungle requires .5vpp I've found that in reality these analog chips have headroom up to almost a 1v.

I'll build a simple through hole component board, take some snaps tonight and start a new thread I think..

Out with the mux in with the mix! :p
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Bratwurst
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Re: TV RGB mod thread

Post by Bratwurst »

Syntax wrote:Even if the Jungle requires .5vpp I've found that in reality these analog chips have headroom up to almost a 1v.
Can confirm, if you look at most datasheets that outline the circuitry behind each pin there are usually clamping/shunting diodes for excess voltage. (within reason)
MarkOZLAD
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Re: TV RGB mod thread

Post by MarkOZLAD »

Syntax wrote:Theres 2 ways to tackle the "mix" method Mark and I use.

Out with the mux in with the mix! :p
Mix is definitely the correct term, I guess mux sounded cool but we clearly aren't mutliplexing.

If your TV matches the pattern of the OSD/Ext RGB Mix/Mux method....and you have through-hole components, the method can be as simple as ungrounding the leg of OSD RGB termination resistors, attach a 75R to them and ground the 75R and then soldering your RGB lines between the two.

If you have SMD you will likely want to remove the SMD termination resistors from the OSD line, find a place on the OSD RGB to inject your RGB and then choose an external RGB inline resistor somewhere around the value that you removed minus 40. Then terminate the Ext RGB to ground via 75R.

Of course, the spreadsheet will provide more accurate Ext RGB inline resistor size choices but these ways are generally close. As Syntax was saying there is generally headroom on the RGB inputs up towards one volt, plus OSD RGB is generally digital so it won't really matter if it gets clipped. It's on full voltage or off.

PS: The general pattern you are looking for is OSD R-> OSD Inline Resistor \/ OSD Termination Resistor -> Capacitor -> Jungle R
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cargo
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Re: TV RGB mod thread

Post by cargo »

Thanks guys. I'll check my work again with a multimeter and look for errors. EDIT: When I check for ohms on each of the three 75ohm resistors I get 75 on red and about 40 on blue and green. Is this normal?

MarkOZLAD wrote:
cargo wrote:Thanks for the reply MarkOZLAD. I didn't do the mux approach because it looked too complicated for me. I would have needed a lot of help and didn't want to impose. I could still try it though.
I reviewed your design and it looks fine. The only thing I can think is that you've messed up in the implementation somehow. Left a blob of solder somewhere or something has a bad connection.

The Red showing is a great sign. Get your multimeter out and take measurements of continuity and resistance to ground on places on the red circuit and then do the same on green and blue and try look for differences.

As for the mux approach, I'd be more than willing to help. I already had notes on this exact chassis and as I'm not advanced enough in my electronics knowledge yet to know the exact method so I was going to recommend the use of a potentiometer to empirically determine the correct resistor size for the mux.

The mux approach is generally WAY EASIER than OSD Snip to implement. Simple, cleaner and better. Just need to study the chassis and the method a bit and think about where you inject your RGB. Note: I rarely use diodes anymore which makes it dead simple. It really isn't something to be scared of.
Last edited by cargo on Tue Aug 21, 2018 6:18 am, edited 1 time in total.
MarkOZLAD
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Re: TV RGB mod thread

Post by MarkOZLAD »

cargo wrote:I'll check my work again with a multimeter and look for errors. EDIT: When I check for ohms on each of the three 75ohm resistors I get 75 on red and about 40 on blue and green. Is this normal?
Is that resistance from ground to blue/green? Should be 75R on all colours.
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cargo
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Re: TV RGB mod thread

Post by cargo »

All three resistors have one leg soldered to the same ground.
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Re: TV RGB mod thread

Post by MarkOZLAD »

cargo wrote:All three resistors have one leg soldered to the same ground.
Thats fine. If you measure resistance from each colour to ground you should get a reading of 75R. If not you have a problem.
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Bratwurst
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Re: TV RGB mod thread

Post by Bratwurst »

Bratwurst wrote:I happen to have this exact same TV and was able to RGB mod it while retaining OSD function today. Remove RR07, CR01, CR02 and CR03, these are tying pins 3 through 6 to ground.

You will want to interrupt the jumper wire that connects pin 6 of the TA1310N jungle to pin 21 of the QA01 microprocessor, making sure there is nothing else on the line going to pin 6. I wired it so the original circuit going to QA01 could be restored with a SPDT switch, including a 1k ohm resistor to ground (which was RR07.) The other end of the switch you want to be 3 volts, I got it by tapping the 7805 and feeding 5V through 20k ohm and 30k ohm resistors in series to ground, and getting 3V in the middle of the resistors. If you refer to page 92 of the TA1310N datasheet there is an example circuit that shows a similar configuration for a three-way switch between RGB (2.1V and up), half-tone (partially transparent OSD? that triggers below 2V) and totally grounded for the other inputs like composite/s-vid/component.

Feed your RGB lines to pins 3-5, making sure you have each line tied to ground with 75 ohms and going through a 104 cap before entering the jungle. Then you just feed 3 volts to pin 6 and that's it. OSD still works. I'm /very/ happy with this set. I'll post pictures later.
Pics of my Toshiba 32A33: https://imgur.com/a/iHQ3JGx
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cargo
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Re: TV RGB mod thread

Post by cargo »

I rebuilt my circuit using fresh parts. Relocated the 0.1uf capacitors (new components as well) to my custom built rgb circuit board (instead of right next to the jungle chip as I originally planned). This is what I got (RGB + blanking wires going directly into jungle [no switch]):

(click for bigger size)
Spoiler
Image Image Image
Image Image
Image Image
I am reading 75ohms on all RGB lines. Tested for continuity and OK for all wires and scart socket. My multimeter reads about 3V for the blanking signal. The fuzzyness on the video game pics is from the camera. Same as before it looks sharp and clean in person (in spite of lack of color). Wish I knew what's wrong.
Last edited by cargo on Mon Aug 20, 2018 3:38 pm, edited 1 time in total.
MarkOZLAD
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Re: TV RGB mod thread

Post by MarkOZLAD »

cargo wrote:Wish I knew what's wrong.
Your red and green lines are connected somewhere, perhaps after the Caps. (I've had this happen before, love a MMB mod! - Mustard,Mustard, Blue). Inspect closely and you'll find it. Very close now.
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cargo
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Re: TV RGB mod thread

Post by cargo »

"mustard mod" :lol: Very on point :D

I went back in and resoldered the pins connecting to the jungle IC but not before placing a piece of shielding tape just to be sure. Apparently that did it! I've yet to mess with brightness and contrast settings but it looks good:

(click for bigger size)
Image Image Image

Image Image Image
Image Image Image

Sometimes during testing I would forget to connect the blanking pin. Since I was using the composite signal for sync the TV would show that image instead. After hours of work it was easy to get confused. On the other hand when doing it on purpose (eg, flipping off RGB on the switch) you still get to see the video game image (albeit composite). It's not mixing but still useful for menu settings.

Thank you MarkOZLAD for all your help.


MarkOZLAD wrote:
cargo wrote:Wish I knew what's wrong.
Your red and green lines are connected somewhere, perhaps after the Caps. (I've had this happen before, love a MMB mod! - Mustard,Mustard, Blue). Inspect closely and you'll find it. Very close now.
Last edited by cargo on Tue Aug 21, 2018 3:17 pm, edited 4 times in total.
Seikenfreak
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Re: TV RGB mod thread

Post by Seikenfreak »

Nicely done. Markozlad diagnosed that like a boss.
MarkOZLAD
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Re: TV RGB mod thread

Post by MarkOZLAD »

cargo wrote:Thank you MarkOZLAD for all your help.
No problem. The assist on the mustard mod diagnoses goes to Syntax who helped me when I had the same issue....
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Syntax
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Re: TV RGB mod thread

Post by Syntax »

MarkOZLAD wrote:
cargo wrote:Thank you MarkOZLAD for all your help.
No problem. The assist on the mustard mod diagnoses goes to Syntax who helped me when I had the same issue....
<---"Tips helmet" :)

Diagnosing faults can be such a pain but mixed colours is a pretty easy one. Its when you see pink that you should turn and run... lol

I tried out a one size fits all approach to the OSD mix yesterday. All the parts used were..

3x 75r
3x 560r
3x 3.9k
3x 100n

It not usually how id do a mod but I just wanted to prove how simple this is.

Also PSA for anyone that's ever modded a SONY CRT.
Enter service menu, find "SBR" and turn it down a few numbers to taste.
Your welcome.
Last edited by Syntax on Tue Aug 21, 2018 10:04 pm, edited 2 times in total.
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cargo
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Re: TV RGB mod thread

Post by cargo »

So if I wanted to begin the homework part for a mix mod where would I start?

I am interested in trying the mix method on a smaller (20 incher) Sony KV-20M20. It's a Trinitron with a mono speaker and one composite input. Probably the most basic Trinitron mentioned in this thread so far. What's cool about this board is that it has empty (but functional) solder pads for RGB and sync! The lines from the OSD go through normal sized resistors (and one SMD resistor under the board) before reaching these empty pads. The board itself has scribblings that almost seem to say "RGB goes here!". It looks like this TV should be easier to work with.

Image Image

The KV-20M20 uses a CXA1870S jungle chip. On the datasheet for this chip it says something very interesting about the behavior of the blanking pin (based on voltage):

(Open spoiler for images)
Spoiler
Image Image
Image
Based on this info am I correct to assume the blanking voltage has to be between 2-3 volts?

Mainboard Schematics (huge image alert):
Spoiler
Image
Last edited by cargo on Wed Aug 22, 2018 8:52 pm, edited 1 time in total.
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Syntax
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Re: TV RGB mod thread

Post by Syntax »

So odd, it screams mod me, but then there's the issue of a digital OSD input to the jungle. Good luck with it.
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cargo
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Re: TV RGB mod thread

Post by cargo »

So you think this isn't a good candidate for a mix mod?
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Syntax
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Re: TV RGB mod thread

Post by Syntax »

Well the screen shot you posted says no rgb under 1v.
Looks like digital to me.
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Re: TV RGB mod thread

Post by MarkOZLAD »

Syntax wrote:Well the screen shot you posted says no rgb under 1v.
Looks like digital to me.
Definite no go. No OSD hijack of any kind possible for analog RGB
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Syntax
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Re: TV RGB mod thread

Post by Syntax »

Heres some pictures of an NEC i just modded.

All I did with this one was snip the OSD RGB pins and the jungle RGB pins then connected them up to my mix circuit.
3x 75r
3x 560r
3x 3.9k
3x 100n

Image

Image

Image

Image

Also heres a pic of an RGBS to composite converter I had to make to trick a modded LG set into RGB mode.
If you feed these sets Csync they switch into Svideo mode, and all my consoles output Csync. Such a pain.

So this little guy can output RGB Csync Composite video and Svideo. I made another neater one in a box inline of a scart cable, this was just a test one.
I feed it RGBS and take RGB Composite video for sync and send that to the LG. (also needs blanking and service menu Scart option on)

Image
Zhoul
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Re: TV RGB mod thread

Post by Zhoul »

RGB mod noob with a couple questions for anyone with a moment to spare.

1) First, I'm gonna get the really stoopid question out of the way: If I use sync-on-luma scart cables, would they be able to function connected to a TV that was RGB modded with csync or sync-on-composite, or could this degrade the picture or cause it to not display at all? See, told ya it was stupid! :lol:

2) Would a 27" Sony (circa 1989?) that lacks s-video be too much for a novice RGB modder?

I'm considering buying a mint condition black 27" Sony. These sets give off a PVM vibe and have a better aesthetic than pretty much any of the newer consumer sets IMO. On the downside, it has manually operated dials on the set to control sharpness, brightness, etc. No idea if these sets have a hidden service menu to adjust settings like geometry (probably not). Thus, adjusting the picture could prove difficult. It only accepts RF and composite as inputs, but likely has RGB located on the jungle chip. Not 100% sure on that, as it's service manual seems to be hidden from the internet.
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Re: TV RGB mod thread

Post by MarkOZLAD »

Zhoul wrote:RGB mod noob with a couple questions for anyone with a moment to spare.

1) First, I'm gonna get the really stoopid question out of the way: If I use sync-on-luma scart cables, would they be able to function connected to a TV that was RGB modded with csync or sync-on-composite, or could this degrade the picture or cause it to not display at all? See, told ya it was stupid! :lol:

2) Would a 27" Sony (circa 1989?) that lacks s-video be too much for a novice RGB modder?

I'm considering buying a mint condition black 27" Sony. These sets give off a PVM vibe and have a better aesthetic than pretty much any of the newer consumer sets IMO. On the downside, it has manually operated dials on the set to control sharpness, brightness, etc. No idea if these sets have a hidden service menu to adjust settings like geometry (probably not). Thus, adjusting the picture could prove difficult. It only accepts RF and composite as inputs, but likely has RGB located on the jungle chip. Not 100% sure on that, as it's service manual seems to be hidden from the internet.
1) Generally TV's aren't modded to accept a certain type of sync. In fact I always just pump sync through an AV port. Some TV's handle all sync types, some have problems with different types of sync.

2) If you tell us the model number/chassis number we can tell you if a TV can be modded. Without a schematic (or opening up the set and checking out the chips in the absence of a schematic) we can't know if a set can be modded. It comes down to each individual TV model/chassis whether modification is possible, cannot really generalise to 1989 Sony no S-video. I would, however, suggest that 1989 is an early model for using the techniques we champion on this thread.
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arithmaldor
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Re: TV RGB mod thread

Post by arithmaldor »

Hey, I'm trying to do an RGB mod on an Emerson SB-315.

Here's the datasheet for the jugle chip:
https://tinkerplunk.files.wordpress.com ... 81eksp.pdf

It seems like it should be possible as it says it has analog inputs, but I can't figure out which ones and how to set the input.

Ok so this doesn't look like the jungle, I'll keep looking.
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MarkOZLAD
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Re: TV RGB mod thread

Post by MarkOZLAD »

arithmaldor wrote:Hey, I'm trying to do an RGB mod on an Emerson SB-315.

Here's the datasheet for the jugle chip:
https://tinkerplunk.files.wordpress.com ... 81eksp.pdf

It seems like it should be possible as it says it has analog inputs, but I can't figure out which ones and how to set the input.

Ok so this doesn't look like the jungle, I'll keep looking.
That's the microcontroller.

Follow the RGB lines and you'll get to the Jungle.
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arithmaldor
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Re: TV RGB mod thread

Post by arithmaldor »

MarkOZLAD wrote:
arithmaldor wrote:Hey, I'm trying to do an RGB mod on an Emerson SB-315.

Here's the datasheet for the jugle chip:
https://tinkerplunk.files.wordpress.com ... 81eksp.pdf

It seems like it should be possible as it says it has analog inputs, but I can't figure out which ones and how to set the input.

Ok so this doesn't look like the jungle, I'll keep looking.
That's the microcontroller.

Follow the RGB lines and you'll get to the Jungle.
Hmmm it just leads to this
Image

Can't find any information on this guy
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arithmaldor
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Re: TV RGB mod thread

Post by arithmaldor »

Jackpot!
Image
This might be tough lol
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MarkOZLAD
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Re: TV RGB mod thread

Post by MarkOZLAD »

arithmaldor wrote:Jackpot!
Image
This might be tough lol
I'm not sure but from the schematics I'm finding for chassis that use this chip, it looks like this chip generally expects Digital RGB signal for OSD.

It MAY be able to be changed to accept analog RGB in service menu but I can't promise anything.

https://datasheetspdf.com/pdf-file/7035 ... 61262BFP/1

http://monitor.espec.ws/files/china_m37 ... 03_135.pdf
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Re: TV RGB mod thread

Post by Sammickk »

two Emerson questions in one night, I just picked up a free emerson CR202EM8 manufactured in 2008.
Would anyone be willing to take a look and see if this TV would be a good candidate for RBG Mod please?

Here is a link to the service manual with all the diagrams.
https://www.manualslib.com/download/700 ... 02em8.html
Akina86
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Re: TV RGB mod thread

Post by Akina86 »

i am new here and not the most technically inclined person, but since finding this forum i have successfully modded 3 TV sets to RGB. i recently pick up a KV-27FV310 in great shape and i am in the process of modding it. everything seemed to be going as planned, but now i am kind of stuck. i have it pretty much done and the picture looks great. the problem is that it has a strange wave just above the middle of the screen that i can't figure out how to get rid of. here is where i stand:

SONY KV-27FV310

RGB signal injected into the jumpers between the OSD chip and the JUNGLE chip.
75 ohm resistors grounded
5v from board going to blanking pin
ground from board going to ground the VGA cable
no modifications to the original signal coming from the OSD chip and there is the wave on the screen.
cut the jumper so only the injected RGB signal from raspberry pi going through it, still wave on the screen.

i don't know a lot about this stuff but i was thinking maybe putting a couple of resistors in line to the blanking pin to possibly bring the voltage down from 5v to maybe 3v to see if that has any affect on the signal. i don't know, though, i am just shooting in the dark on this right now. any help would be greatly appreciated. below are some shots of where i am at:

Image
Image
Image
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