Sony Trinitron S-Video/Composite Mod (RF-Only TV) SOLVED

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deeplistened
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Re: Sony Trinitron S-Video/Composite Mod (RF-only TV)

Post by deeplistened »

This is awesome! Thank you. I’ll let you know how it goes.
swamp_dude
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Re: Sony Trinitron S-Video/Composite Mod (RF-only TV)

Post by swamp_dude »

matt wrote:For what it's worth, I was able to add S-Video to a KV-20S90 (BA-4D chassis) a few days ago. It should work with other 13" and 20" BA-4/4D TVs. The schematic is slightly different from the BA-5 models, but it's similar enough that some of what I did may be relevant.

Sorry, no pics - I didn't think to take any and have since removed the mod since I don't have an immediate use for it.

Luma goes through the rear A/V jack (on the BA-4D, Luma and Video 1 both go to pin 4 of the Jungle IC). Chroma goes to pin 2, with a 75ohm terminating resistor and a 0.01uf coupling capacitor.

By itself, this doesn't do anything - the chroma input is disabled and the picture will still be black & white. Fortunately, this can be changed in the service menu. The A/V input setting are governed by ID-1, which has a default value of 3 on my TV. To enable S-Video, add 16 to whatever its initial value was (in this case, it should be changed to 19). The ID bits appear to be the same on BA-5 models.

Now the picture will be in color, but very blurry since it's running the video through the luma trap filter. Disable CTRP in the service menu to clean it up. This means that composite will now look terrible, so you'll have to go back to the service menu every time you want to switch between composite and Y/C.

I was pleasantly surprised with how good the picture was with this mod. It's incredibly crisp and just a hair below RGB.
Did you try to connect it to the S-Video switch pin on the micon?
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matt
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Re: Sony Trinitron S-Video/Composite Mod (RF-only TV)

Post by matt »

swamp_dude wrote:Did you try to connect it to the S-Video switch pin on the micon?
Sorry, I didn't notice you post until now.

But anyhow, no I didn't. I don't think it would do anything. With these BA-4 chassis TVs, the models with S-Video all use a separate comb filter for composite and the signals are routed differently from the ones that are composite-only. This is why the luma trap filter needs to be disabled in the service menu for the mod to work properly. It's a pain if you want to switch between composite and S-Video on a regular basis, but if you just plan on using S-Vid (or combine it with an RGB or component mod), it works well.
swamp_dude
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Re: Sony Trinitron S-Video/Composite Mod (RF-only TV)

Post by swamp_dude »

matt wrote:
swamp_dude wrote:Did you try to connect it to the S-Video switch pin on the micon?
Sorry, I didn't notice you post until now.

But anyhow, no I didn't. I don't think it would do anything. With these BA-4 chassis TVs, the models with S-Video all use a separate comb filter for composite and the signals are routed differently from the ones that are composite-only. This is why the luma trap filter needs to be disabled in the service menu for the mod to work properly. It's a pain if you want to switch between composite and S-Video on a regular basis, but if you just plan on using S-Vid (or combine it with an RGB or component mod), it works well.
Yeah, I noticed they are a bit different, but it seems like the difference is on the composite signal path only, and looking at the s90 service manual it looks like the traces for the switch pin are all there (I haven't tested it yet) it goes straight to the s-video port, the only mystery is how the port activates it, I guess I'll apply the voltage specified on the micon datasheet to the pin and see if it does anything, but thanks anyway.
retromaniak
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Re: Sony Trinitron S-Video/Composite Mod (RF-only TV)

Post by retromaniak »

Hi, i have install into my tv (Roadstar CTV-1010 XKT) S-Video Signal Line. My question is. Will such a simple connection as in the diagram below work correctly? I also attach a link to the Service Manual. https://drive.google.com/file/d/10jzUd1 ... sp=sharing
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BazookaBen
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Re: Sony Trinitron S-Video/Composite Mod (RF-only TV)

Post by BazookaBen »

retromaniak wrote: Will such a simple connection as in the diagram below work correctly?
hard to know for sure. How will the TV know to switch the s-video signal? Maybe you can unlock it in the service menu?

And don't forget that these signals usually need 75ohm termination to ground, and usually a 0.1uf cap between signal and the jungle chip
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Re: Sony Trinitron S-Video/Composite Mod (RF-only TV)

Post by jeffez »

I thought i might give an update. Here is my latest diagram minus the composite input. As BazookaBen pointed out, having composite the way i had it would affect the svideo signal. To use composite you would just need to use an external adapter.

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Also i have revised my switching PCB. I was able to simplify the circuit by adding another CD4053B. The last one had some issue with it so i decided to just start again. Just waiting on fabrication. Hopefully it works this time and i can show how it fits in the above diagram.

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Re: Sony Trinitron S-Video/Composite Mod (RF-only TV)

Post by jeffez »

New PCB tested and working. This replaces all the breadboard wiring I had and it can now be installed inside the tv somewhere. This basically acts like a 6PDT switch that is controlled by a HIGH/LOW signal to switch between TV or S-Video. The pin on the OSD chip that I ungrounded to enable the TVs video mode reads 5V in video mode and 0V in RF/TV mode. This means no external switch is needed since pressing 'video' on the TV remote is what makes it switch it over to S-Video.

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BazookaBen
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Re: Sony Trinitron S-Video/Composite Mod (RF-only TV)

Post by BazookaBen »

What was the urpose of the high/low signal before the mod? Seems like it would already switch between TV and video
jeffez
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Re: Sony Trinitron S-Video/Composite Mod (RF-only TV)

Post by jeffez »

BazookaBen wrote:What was the urpose of the high/low signal before the mod? Seems like it would already switch between TV and video
Normally yes but not on this set because it's rf only. Instead it goes straight to ground disabling Video mode. There's an S-Video set schematic which shows it being used. It's pin 36 marked "TV/AV"
nmur
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Re: Sony Trinitron S-Video/Composite Mod (RF-only TV)

Post by nmur »

Hey, just stumbled across this thread, and looks like you've done an awesome job here, well done.

I've recently picked up a very similar Australian set:
Model: KV-1415AS
Jungle: CXZ1213BS
IF201: IFD-380A
Chassis: G3E

It's RF only as well, and I have the service manual. The schematics show circuitry for two composite video inputs, however this area on the board in my actual set is totally unpopulated. It looks like you're basically solved this mod to a degree where these schematics won't help you though.

From glancing between your latest diagram and my unit's schematics, adding S-Video might be the same procedure, assuming there's no big difference between ICs. Audio looks different, my schematic involves a switch in that circuit, probably for the 3.5mm jack output.

I can solder/mod stuff, but I have little clue how these circuits work. If you have any thoughts on my set before I go ahead and try stuff, it would be really appreciated.
marcelosofth
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Re: Sony Trinitron S-Video/Composite Mod (RF-only TV)

Post by marcelosofth »

nmur wrote:Hey, just stumbled across this thread, and looks like you've done an awesome job here, well done.

I've recently picked up a very similar Australian set:
Model: KV-1415AS
Jungle: CXZ1213BS
IF201: IFD-380A
Chassis: G3E

It's RF only as well, and I have the service manual. The schematics show circuitry for two composite video inputs, however this area on the board in my actual set is totally unpopulated. It looks like you're basically solved this mod to a degree where these schematics won't help you though.

From glancing between your latest diagram and my unit's schematics, adding S-Video might be the same procedure, assuming there's no big difference between ICs. Audio looks different, my schematic involves a switch in that circuit, probably for the 3.5mm jack output.

I can solder/mod stuff, but I have little clue how these circuits work. If you have any thoughts on my set before I go ahead and try stuff, it would be really appreciated.
Hello friend, I have a CRT '21 TV and the Component input has the image flickering, I connected the Y to the Composite AV1 input, the perfect and stable image appears, but black/white, it is possible for me to inject the other 2 cables from the Component in Composite to be colored?
nmur
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Re: Sony Trinitron S-Video/Composite Mod (RF-only TV)

Post by nmur »

Waiting on some parts before I try it, but I'm going to go ahead with this, as it looks pretty equivalent to your mod:

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BazookaBen
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Re: Sony Trinitron S-Video/Composite Mod (RF-only TV)

Post by BazookaBen »

Ugh, don't give youself worse sound though. Grab some external speakers or a headphone amp.
nmur
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Re: Sony Trinitron S-Video/Composite Mod (RF-only TV)

Post by nmur »

BazookaBen wrote:Ugh, don't give youself worse sound though. Grab some external speakers or a headphone amp.
Oh definitely, I've got floorstanding speakers and headphones with amps for my actual CRT setups - having audio with this mod is just for completeness really. I picked up this set for free and plan to pass it on once it's modded, and I don't know how the next person would choose to use it.
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Re: Sony Trinitron S-Video/Composite Mod (RF-only TV)

Post by jeffez »

nmur wrote:
BazookaBen wrote:Ugh, don't give youself worse sound though. Grab some external speakers or a headphone amp.
Oh definitely, I've got floorstanding speakers and headphones with amps for my actual CRT setups - having audio with this mod is just for completeness really. I picked up this set for free and plan to pass it on once it's modded, and I don't know how the next person would choose to use it.
Awesome to see a similar rf only set getting the same treatment.
With the audio you'll see on my diagram it goes into 'AF IN' on the IF chip. I put it here because it seemed to be the right spot for the signal to go to utilise the TVs existing audio circuitry including it's volume control. No need for external speakers, amp etc. Yours appears have the same option. Might take some trial and error to find the right spot but maybe behind C211.
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Re: Sony Trinitron S-Video/Composite Mod (RF-only TV)

Post by jeffez »

Here's a rough illustration of how my switching circuit fits it. This is just a low res version as the original image i did is quite large.
The main thing that is new here is where it taps into the 5V signal to detect when "Video" is pressed on the remote. This is the red line on the diagram off to the left. Pin 36 (TV/AV) on what looks an IC that handles OSD and other related things.
Image
nmur
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Re: Sony Trinitron S-Video/Composite Mod (RF-only TV)

Post by nmur »

jeffez wrote:
nmur wrote:
BazookaBen wrote:Ugh, don't give youself worse sound though. Grab some external speakers or a headphone amp.
Oh definitely, I've got floorstanding speakers and headphones with amps for my actual CRT setups - having audio with this mod is just for completeness really. I picked up this set for free and plan to pass it on once it's modded, and I don't know how the next person would choose to use it.
Awesome to see a similar rf only set getting the same treatment.
With the audio you'll see on my diagram it goes into 'AF IN' on the IF chip. I put it here because it seemed to be the right spot for the signal to go to utilise the TVs existing audio circuitry including it's volume control. No need for external speakers, amp etc. Yours appears have the same option. Might take some trial and error to find the right spot but maybe behind C211.
Thanks for the tip, I think you're probably right. There's a headphone output on the front of this set so it will be interesting to see if it works with this mod too.

I don't have any RCA sockets yet, but I've just performed the video mod, and it looks excellent compared to RF! This is my first input mod, so it's really satisfying seeing it work.
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Re: Sony Trinitron S-Video/Composite Mod (RF-only TV)

Post by jeffez »

nmur wrote: Thanks for the tip, I think you're probably right. There's a headphone output on the front of this set so it will be interesting to see if it works with this mod too.

I don't have any RCA sockets yet, but I've just performed the video mod, and it looks excellent compared to RF! This is my first input mod, so it's really satisfying seeing it work.
Yeah that tube would never have looked so good being restricted by RF all this time. Hopefully more people find this and we can save a few more old sets like this.
nmur
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Re: Sony Trinitron S-Video/Composite Mod (RF-only TV)

Post by nmur »

jeffez wrote:
nmur wrote: Thanks for the tip, I think you're probably right. There's a headphone output on the front of this set so it will be interesting to see if it works with this mod too.

I don't have any RCA sockets yet, but I've just performed the video mod, and it looks excellent compared to RF! This is my first input mod, so it's really satisfying seeing it work.
Yeah that tube would never have looked so good being restricted by RF all this time. Hopefully more people find this and we can save a few more old sets like this.
I wired up the audio input today, and found that the C212 capacitor I was originally planning to connect behind was actually just a jump on this board, which reduced the number of options to try, and was a success! I will make the mod more permanent in the near future.
jeffez
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Re: Sony Trinitron S-Video/Composite Mod (RF-only TV)

Post by jeffez »

nmur wrote:
jeffez wrote:
nmur wrote: Thanks for the tip, I think you're probably right. There's a headphone output on the front of this set so it will be interesting to see if it works with this mod too.

I don't have any RCA sockets yet, but I've just performed the video mod, and it looks excellent compared to RF! This is my first input mod, so it's really satisfying seeing it work.
Yeah that tube would never have looked so good being restricted by RF all this time. Hopefully more people find this and we can save a few more old sets like this.
I wired up the audio input today, and found that the C212 capacitor I was originally planning to connect behind was actually just a jump on this board, which reduced the number of options to try, and was a success! I will make the mod more permanent in the near future.
Good stuff!
I'm finally up to finishing my one up with the switching pcb. Might put some pics up soon.
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WOW90
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Re: Sony Trinitron S-Video/Composite Mod (RF-only TV) SOLVED

Post by WOW90 »

Hi there. I got my hands on an old 1995 Toshiba 1400RN set that has only RF input. I wanted to do an RGB mod to it, but since the Jungle IC can only output 8bit RGB signal that is not the case. The set is extremely old and I could not find any schematics for it aside for schematics to a similar model, Toshiba 1400RBT. Looking at the mobo the chips present on it are a Mitsubishi 34300-587SP. That's the OSD chip for which I was not able to find any datasheet but luckily the Toshiba 1400RBT schematics have the pinouts for a similar model, a Mitsubishi 34300-583SP that hopefully works in a similar fashion. The jungle IC is a Toshiba TA8718N for which I found the PDF datasheet. Then a T51496P that seems to be taking care of the demodulation process, sadly I was only able to find a partial datasheet only in the form of a low quality image. For last the audio amplifier is a Philips TDA7052 that takes care of the audio out to the speaker, and thankfully for this one I got the full datasheet PDF in high quality. Here I have posted some pics of the schematics of the chips that the TV has and a schematic of the entire set. I apologize for the low quality image but I was not able to find anything higher quality online. https://imgur.com/a/JeOCBu2
Here instead I posted a link to the PDF datasheets I was able to find online https://drive.google.com/drive/folders/ ... sp=sharing
Anyhow, since I managed to do a Composite mod (basically, desoldered pin 9, and pin 18 of the T51496P demodulation IC, which are respectively Audio Driver Output and Video Output, to bring them off circuit in order to have my have my own Audio Input and Video Input enabled, soldered on pin 29 of the TA8718N IC my Composite input, with a 1uF cap and a 75R parallel resistor to ground.) I was wondering if, based on the schematics, is possible to do a S-video mod for my set. I apologize if I am bothering but since this is my first time attempting such a mod I am afraid I will mess something up, therefore I came here asking for guidance.
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BazookaBen
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Re: Sony Trinitron S-Video/Composite Mod (RF-only TV) SOLVED

Post by BazookaBen »

It has a Y and C inputs. So see if you can find any larger models with the same chip that have s-video, and just copy that circuit.

If you can't find another model, then you ust have to figure out what sort of termination the chip is looking for. Probably 75ohm like you see on other mods here.

Then, you have to figure out how to get the TV to switch to that input. Maybe it's automatic, maybe it's a service mode tweak, maybe you have to disable RF or composite to get it to work.
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WOW90
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Re: Sony Trinitron S-Video/Composite Mod (RF-only TV) SOLVED

Post by WOW90 »

BazookaBen wrote:It has a Y and C inputs. So see if you can find any larger models with the same chip that have s-video, and just copy that circuit.

If you can't find another model, then you must have to figure out what sort of termination the chip is looking for. Probably 75ohm like you see on other mods here.

Then, you have to figure out how to get the TV to switch to that input. Maybe it's automatic, maybe it's a service mode tweak, maybe you have to disable RF or composite to get it to work.
First of all thank you so much for actually replying, since I managed to inject my own Composchyte signal, the set seems to switch to that as long as pin 19 of the T51496P demodulation IC is off circuit, as soon as I resolder that pin back, the set does not display the signal anymore. I have ordered some spare parts to perform the mod, I will report back if I am successful
jeffez
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Re: Sony Trinitron S-Video/Composite Mod (RF-only TV) SOLVED

Post by jeffez »

WOW90 wrote: Anyhow, since I managed to do a Composite mod (basically, desoldered pin 9, and pin 18 of the T51496P demodulation IC, which are respectively Audio Driver Output and Video Output, to bring them off circuit in order to have my have my own Audio Input and Video Input enabled, soldered on pin 29 of the TA8718N IC my Composite input, with a 1uF cap and a 75R parallel resistor to ground.) I was wondering if, based on the schematics, is possible to do a S-video mod for my set. I apologize if I am bothering but since this is my first time attempting such a mod I am afraid I will mess something up, therefore I came here asking for guidance.
Am I understanding correctly that you are managing to get a composite signal to work by sending it to pin 29 (with a coupling capacitor and termination resistor)? Note that pin is for luminance and so if it is working then chroma and sync must be managing to make there way through the circuit to where they need to go. Looks like pin 7 and 16.
jeffez
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Re: Sony Trinitron S-Video/Composite Mod (RF-only TV) SOLVED

Post by jeffez »

I have now finally officially finished this mod! Works just like it would have if the tv came with s-video.

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BazookaBen
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Re: Sony Trinitron S-Video/Composite Mod (RF-only TV) SOLVED

Post by BazookaBen »

Where'd you find that s-video connector with the notch on top? All the ones I found at digikey didn't have that so that means I had to modify them so the ps1/2/3 s-video cable would fit.
jeffez
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Re: Sony Trinitron S-Video/Composite Mod (RF-only TV) SOLVED

Post by jeffez »

BazookaBen wrote:Where'd you find that s-video connector with the notch on top? All the ones I found at digikey didn't have that so that means I had to modify them so the ps1/2/3 s-video cable would fit.
I found them on eBay from a local seller in Aus, but it looks like you can buy them from china as a last resort. The only difference is mine also came with a pcb that goes on the back making it easier to install and glue in place.
MarkOZLAD
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Re: Sony Trinitron S-Video/Composite Mod (RF-only TV) SOLVED

Post by MarkOZLAD »

Awesome mod.

Lots of wires!
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Re: Sony Trinitron S-Video/Composite Mod (RF-only TV) SOLVED

Post by jeffez »

MarkOZLAD wrote:Awesome mod.

Lots of wires!
Thanks, yeah keeping the stock RF mode pretty much doubled the amount needed
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