Component Video mod for curved screen Sony Trinitrons

[matt]

I mentioned briefly in the TV RGB mod thread that I'd been experimenting with adding component video to curved screen Sony Trinitron TVs. So far, I've gotten it to work on 3 different models, all with the BA-4D chassis although I imagine it would also work on BA-4 and AA-2D models too. The mod is not difficult and the results are very good. This particular TV is a KV-27V42.

If you look at the schematic, you'll notice that the jungle chip has a set of pins labeled "YUVSW, E-YIN, E-RYIN, and E-BYIN" (36 to 40). These are used by the PIP circuit on some of the 27" models. YUVSW is the blanking pin, and the 3 YUV inputs can take external component signals. YUV input can be disabled via the I2C bus, but fortunately for us Sony has left them active and all that needs to be done is to connect the blanking circuit and hook up the signals. As usual, 75 ohm terminating resistors and 0.01uF coupling capacitors are required.

The 27V42 doesn't have PIP, but some of the components are populated anyways - most notably the resistors & diodes on the blanking circuit. Capacitors C370-372 are present on PIP models, vs C380-382 on models with no P board:



The 3 YUV lines and blanking all go to a 15-pin connector near the jungle chip. The connector is missing on the V42, but it provides some useful connection points:



Everything is fairly close together on the bottom of the PCB. I removed C380-382 to test out the inputs (before taking this photo). It's a simple matter to relocate these caps to C370-372, since they are the correct value (0.01 uF). The YUV blanking is already connected to pin 11 of the PIP header:



For this TV, I chose to install a header where the PIP connector should be and run the wires to RCA jacks on the back of the shell. A 2-row DIP header will work if you pull out alternating pins. Pin 4 on the PIP header is unused, so I connected it to +5v through a 1k resistor to use with the blanking switch. I added 75 ohm resistors to the R-Y and B-Y RCA connectors (not Luma, more about that later). Of course I didn't think to take photos of the top of the board, but you can use your imagination:



The catch is that the TV takes sync from the composite or S-Video signal, not from the YUV inputs. As with the OSD mods, the picture will have excessive horizontal shift if we use a composite input for sync, so this has to go through the AV-1 S-Video jack. There are a few ways to make this work, but the simplest I found was to connect the Luma signal to both E-YIN on the jungle chip and the S-Video input. Because it already has 75 ohm termination, we don't need to add another resistor to the Y input jack.

To to make this work, we also need to ground the S-Video switch pin. This means that, to maintain functionality of the S-Video input, the blanking switch needs to have 3 poles: one for +5v to the blanking pin, one to enable the S-Video input, and one to connect the sync signal. I added a header the the empty jumper positions on the right side of the photo to connect the sync & S-video switch lines to the blanking switch:



The picture quality is excellent - just as good as the OSD mods. IMO it's better than the native component input on the later flat Trinitrons, as there is no artificial sharpness or other image "enhancement" to degrade the picture (cue obligatory SOTN screenshot). Apologies for the bad convergence. I should note that I disconnected the velocity modulation coil before doing the mod.

Spoiler

*EDIT* - The following paragraph appears to have been due to poor calibration of the TV itself, not the mod. I didn't notice any color balance issues on other Trinitrons that I subsequently tested the mod with. Please disregard this section.

One thing I noticed is that the color balance is slightly off with the component mod - it's a little on the purple side. I don't know exactly why this is - it could be a clamping issue or it could stem from splitting the luma signal and using it for sync. This can be corrected by adding inline resistors to the R-Y and B-Y lines (30 to 50 ohms seems to work), or you can change the color balance in the service menu. This is an area that needs some work. You can see it slightly in the following photo (the KV-27S42 on the right is running RGB):

Spoiler

Two of the main benefits of this mod vs the usual RGB mod are that the OSD is unaffected and, unlike RGB, you can change the color saturation via the user menu. You can even use the AXNT "red push" if you want (I actually like this feature).

If you want, you can enable PIP through the service menu by changing the value of ID-6 to 7. However, it doesn't do much except show which channel the PIP is supposed to be displaying. I think the blanking signal comes from the PIP chip rather than the micon.

Since modding the 27V42, I've gotten it to work on a KV-27S42 and a KV-20S90. The 20S90 was surprising to me since it uses a different PCB from the 27" models and the YUV pins are left floating. I have a couple of other Trinitrons I haven't tested yet, and I'd be curious to see what other chassis variations are compatible.

[BazookaBen]

Very cool!

I think this might work on BA-5 sets too because the jungle chips usually have the same YUV pins for PIP.

[matt]

Probably, just try activating YUVSW. If it blanks the screen you should be good to go.

[MarkOZLAD]

> IMO it's better than the native component input on the later flat Trinitrons, as there is no artificial sharpness or other image "enhancement" to degrade the picture (cue obligatory SOTN screenshot)

This is the problem I see with most component sets, it's not the component signal that's a problem it's the "enhancements" that the manufacturers thought was a good idea is actually not.

Mod looks great.

[tongshadow]

Good job! Does the sharpness setting work?

[matt]

Good job! Does the sharpness setting work?

Nope. That is a good thing, since sharpness serves no useful purpose with component.

[Osirus]

This is the problem I see with most component sets, it's not the component signal that's a problem it's the "enhancements" that the manufacturers thought was a good idea is actually not.

Same with modern HD sets. Crap like "Edge Enhancement", "Noise Reduction", and "Motion Plus" all need to be turned off immediately.

[stonesipping]

If you look at the schematic, you'll notice that the jungle chip has a set of pins labeled "YUVSW, E-YIN, E-RYIN, and E-BYIN" (36 to 40). These are used by the PIP circuit on some of the 27" models. YUVSW is the blanking pin, and the 3 YUV inputs can take external component signals. YUV input can be disabled via the I2C bus, but fortunately for us Sony has left them active and all that needs to be done is to connect the blanking circuit and hook up the signals. As usual, 75 ohm terminating resistors and 0.01uF coupling capacitors are required.

Are the I2C Bus Registers flashed to the chip, or are they adjustable from the service menu?

The setting for EW-SY is at BIT1 of "∗ ∗ ∗ 0 1 0 0 1 09 H" from the chip schematic CXA2025AS (inside AA-2D chassis).

If EW-SY is set to 1 then the E-YIN pin becomes invalid, and so the chip uses the internal Y (Pin 4) signal whether YUV SW is high or low. If EW-SY set to 0 then the chip still uses the internal Y (Pin 4) signal when YUV SW = low BUT external Y/color difference signal is selected when YUV SW = high.

The CXA2025AS datasheet (http://pdf.datasheetcatalog.com/datashe ... 801857.pdf) says that EW-SW = 0 as standard, meaning that and all three signals could be injected to the labeled pins, with grounding and coupling, but i have yet to look at my tv set to inspect the actual usage.

[matt]

You can change some of these settings via the ID bits in the service menu, although they don't seem to directly correlate with the I2C bus registers. I have no experience in this area and don't know much about how it works; the most insight I've seen was from the "PCB Junkie" YouTube videos, which are worth watching if you haven't already:

https://www.youtube.com/watch?v=ANSxASanZes

I spent a bunch of time comparing the ID bit settings of various TVs before trying the mod, because I'd assumed that YUV might be disabled on some models. It was insightful but I wasn't able to find a setting that would disable the YUV blanking pin, which surprised me somewhat.

I don't have access to any 32 or 35" Trinitrons. I imagine it would work, though, since all of them have variants that include a YUV-based PIP board. Please post your results if you're able to try it! If the blanking switch works, the rest of the mod should be possible.

[matt]

Since I made this post, I've had a few ideas to improve my 27V42 mod, but I ended up injuring my back at work and didn't feel it was a good idea to lift the TV off the floor where I'd left it and on to my work bench. So instead, I spent the last week working on a KV-13M42, which is much lighter and easier to pick up.

This one has been very interesting. The component mod works fine on this model, although I was able to tweak things a bit in a way that I think works a little better. One fun thing about this TV is that it only has one video input, and I found that I could use the audio switch signal from the micon (for the unused AV port) to trigger YUV blanking. This gives the TV an extra component input that's selectable via the remote or the front panel. I'll try to make a writeup of what I did in the next day or two.

The following clip is me switching between PS1 composite, Gamecube component, and RF fuzz just by pressing the TV/Video button:

https://imgur.com/8lmHZR3

[stonesipping]

You can change some of these settings via the ID bits in the service menu, although they don't seem to directly correlate with the I2C bus registers. I have no experience in this area and don't know much about how it works; the most insight I've seen was from the "PCB Junkie" YouTube videos, which are worth watching if you haven't already:

https://www.youtube.com/watch?v=ANSxASanZes

Thank you. For my level of skill it looks like the I2C registers are basically set and not editable. Of course I'm hopeful the chip defaults 0 for external E-YIN option are left unchanged. The other option being use of your the internal Y sync workaround if E-YIN is programmed as invalid.

I spent a bunch of time comparing the ID bit settings of various TVs before trying the mod, because I'd assumed that YUV might be disabled on some models. It was insightful but I wasn't able to find a setting that would disable the YUV blanking pin, which surprised me somewhat.

On a side note, i'm curious if 2V will be enough to blank YUVSW. Will probably try a voltage divider if/when i get to try the mod.

[matt]

Thank you. For my level of skill it looks like the I2C registers are basically set and not editable. Of course I'm hopeful the chip defaults 0 for external E-YIN option are left unchanged. The other option being use of your the internal Y sync workaround if E-YIN is programmed as invalid.

Apparently, I originally misunderstood the data sheet - I assumed that a value of 1 would disable all 3 external YUV pins, which isn't the case. Assuming they are still in phase, I imagine using internal Y and external Pb/Pr could work better than my current mod. It's possible that it would bring the brightness and color saturation of the YUV input more in line with composite, and you wouldn't have to split the Y signal for sync.

Either way, it looks like pretty much any Trinitron with external YUV pins on the jungle chip should be a candidate for a component mod - it doesn't seem like there's a way to completely disable that function.

Something like the PCB Junkie mod chip (http://pcbjunkie.net/index.php/projects ... e-modchip/) could be very useful here. If the I2C bus can be controlled to change the EY switch and, for those models that have it, the RGB 1 input, you could significantly improve the functionality of these TVs, making any of them capable of RGB, component, and Svideo without the side effects of the OSD hack. Ideally, you could make a device that would compensate for the horizontal shift on each input and perhaps even enable the blanking pins so that an external switch isn't necessary.

On a side note, i'm curious if 2V will be enough to blank YUVSW. Will probably try a voltage divider if/when i get to try the mod.

It should work, according to the data sheet. On my CXA2061 the Vth is listed as 0.7v so I'd guess 2v should be fairly universal.

My 13" Trinitron currently is using 6.4v for blanking, since it's what is going to the audio switch IC and I haven't taken the time to make a voltage divider that will still keep both functions. I haven't had any problems (and I think it will be OK since the YS1 pin apparently has a function that requires 7v), but it's something I'm planning to figure out soon.

[Zebidee]

Nice modding Matt!

I guess it goes without saying the the GreenAntz RGB to component transcoder should work well with this or any other SDTV that takes component inputs.

GreenAntz does analogue RGB to YPbPr transcoding that does not have any of the lag associated with digital processing. VGA input version can accept either separate H&V sync or composite sync. GreenAntz outputs a composite sync signal with superior sync tip integration into Y that delivers improved image brightness and colour definition. It is better than anything else in this space and price range.

Currently available as VGA RGBHV+RGBs input. SCART RGB input version coming soon.

Component modding is often easier and less "invasive" than RGB modding. Many TVs cannot be RGB modded but can be component modded. With GreenAntz in your toolkit there are a lot more TVs affordably available for arcade cabs and retrogaming generally.



There is more on it here:
http://forum.arcadecontrols.com/index.p ... 245.0.html

PM me if interested to buy

[matt]

As promised, the latest component mod I did was on my 13" KV-13M42. This TV has mono sound and a single AV input. However, a second video input can be enabled in the service menu by changing the value of ID-1 to 3. I decided to use this for the mod's sync input.

The mod was mostly the same as the 27V42, although I found that the component input was to bright. Adding a 50 ohm resistor to the Y input jack brought it down to a similar level as the composite input. I did not notice any difference in color balance between YUV and composite.



The 13" and 20" BA-4D Trinitrons use a different board design than the 27" models. It's simpler, with fewer AV inputs and none of the circuitry for the PIP board. However, the component mod still works. This model uses the CXA2061S jungle chip, which is also found on most of the BA-4 Trinitrons. It appears to be nearly identical to the CXA2133 from the KV-27V42, and the YUV input pins are the same:



Unlike the 27" models, pins 36 to 39 aren't connected to anything and are left floating. Without the decoupling capacitors on the YUV pins you'll see a bunch of random chroma interference if blanking is triggered by itself (which doesn't affect the mod at all). I am using video 2 (pin 41) for sync:



One useful feature of this TV is that audio switching is controlled from the Micon with +5v signals (although in real life it was 6.4v). With the addition of a few missing components, we can enable the second audio input and harness the switching voltage for blanking:



The second AV input (from the front panel) is missing a handful of components. To enable sound from Video 2, we have to reconnect audio 2 to pin 5 of IC 201. Switching voltage goes to pin 4:



To make this work, the following components must be populated: R072 (220 ohms), R086 (10K ohms), R202 (470K ohms), C202 (1 uF), and D202 (10v zener diode). D202 is for over voltage protection, and the mod will still work without it. Jumpers JW 067 and 080 should also be connected:

Spoiler

There is a set of unused jumpers holes near the tuner that I populated with DIP headers and used for YUV and audio inputs:



The 3 video signals have 75 ohm terminating resistors to ground, and the Pr/Pb signals go through 0.01 uF coupling capacitors. Audio goes to the unused right audio channel of J201:



On the jungle chip side, Pr and Pb go to pins 38 and 39. Y is split; goes to pin 37 though a 0.01uF cap, and to pin 41 through a 1uF cap (C204). There is an unused jumper on pin 41 that made a useful connection point. The original schematic shows a 10v zener diode (D204) on the video input, which I added for completeness' sake. The 3 680 ohm resistors on the right of the photo are from an old RGB mod that I've since removed and aren't related to the component mod at all:



*EDIT* - There is a problem with the auto-blanking mod. I found out later that the voltage divider was pulling down the 9v power supply too much, causing the TV to intermittently shut off. I haven't taken the time to figure out a better method yet. Unless you're willing to troubleshoot this part, you may be better off with a manual blanking switch!


For blanking, pin 26 is connected to the leg of R072 though a 24k ohm resistor, and to ground via a 22k ohm resistor. This creates a voltage divider that brings down the 6.4v to approximately 2v for blanking, while preserving the audio switch function. The end results is that the TV will automatically switch to component whenever Video 2 is selected:



To enable sound on Video 2, pin 3 from the missing right audio switch (IC 200) is jumped to pin 5 of IC 201:



The YPbPr and audio is hooked up through 4 RCA jacks in the back of the case. The Y connector has an inline 50 ohm resistor to bring the brightness in line with the composite input:




In the end, this mod works very well. It effectively gives the TV an extra input, which can be selected seamlessly from the remote or the front TV/Video button. Quality is excellent, on par with an RGB mod (apologies again for the bad convergence, fixing it is the next item on my to-do list). My camera's white balance was a little off; the picture looks better in person:

Spoiler

In the end, while the mod works very well, I'm not sure that component video is the best option for a consumer TV of this size. The phosphor pitch is very coarse, and while 240p consoles look fantastic, none of them support component out of the box. Ironically, all of the systems that do have native component output don't look their best and a lot of detail is lost. While this is a good proof of concept, a component mod is better suited for the larger Trinitrons unless you're using HD retrovision cables or already have a converter set up.

I'm very happy with the automatic blanking switch. This could be implemented on the 20" models as well, although you'd have to sacrifice one of the video inputs. The 27" Trinitrons are more complicated, since they have a separate A/V switch that seems to controlled via the I2C bus, and the composite inputs are routed through a separate comb filter. I'm not sure if it can be made to work or not, but it's worth looking into.

[BazookaBen]

Great work!

But the colors do look a little off. Like a little dark and oversaturated? Did you check continuity for Y to see if it was going anywhere else on the board that might change the values you need for the resistor or capacitor?

I ask because, on the s-video mod I did to a 13fm12, the Y input needed a 10uf cap, maybe because it was fed to two different chips on the board (microcon and jungle), while chroma needed 0.1uf.

[matt]

That's just my camera's automatic white balance. It looks great in person (probably should have noted that).

In any case, color saturation can be adjusted, so if the colors are too strong that can be changed in the user menu.

[Zebidee]

Nice work.

[KPackratt2k]

Hello, I was wondering if it would be possible to YPbPr (Component) mod a Sony KV-20EXR20. I got this TV recently and I was able to find a service manual for the KV-27EXR25, which has an identical chassis to this model. The KV-27EXR25 happens to have a Picture-In-Picture mode which is disabled on my KV-20EXR20, and from the looks of it, it too uses a variant of YPbPr for its PIP feature.

After carefully taking photos of the inside of my TV, I can confirm that it does have the PIP circuitry intact even though the feature is disabled. I can access its service menu by pushing a paper clip into a hole above the S-Video connector while turning the TV on, if I need to make adjustments there.

Thanks in advance.

[stonesipping]

I'm having an issue with a Component Mod to my Philips tv, where the Green is overwhelming even the black levels seem overdriven. Sony TVs have multiple Red/Green/Blue Cutoff, Drive and other options in the service menu but the Philips has only one individual color adjustment in the service menu and dialing it down does not come close to evening out the levels.

The Sync line is on Green with Component and I'm wondering if that is somehow connected with the overdriven color problem, any suggestions on how to proceed?

[matt]

What model TV is your Philips?

With the Sony mod, I found that the brightness level was off compared with the composite/Svideo inputs. I thought this may have been due to the sync causing the Luma signal to be clamped at 0.3v higher than normal. This didn't affect the overall color balance, though.

[stonesipping]

What model TV is your Philips?

20PT633R01 model, I think its the L01.1U Chassis, which is what I found on the service manual.
link to pdf: https://www.dropbox.com/s/g3fo6hq7tv434 ... u.pdf?dl=0

With the Sony mod, I found that the brightness level was off compared with the composite/Svideo inputs. I thought this may have been due to the sync causing the Luma signal to be clamped at 0.3v higher than normal. This didn't affect the overall color balance, though.

The green is definitely stronger. I've tried a few configurations to put a variable resistor pot (before and after clamping) on the green input line, but it never changed the strength of the color. Then I tried to change the B+/Screen pot on the flyback. Not sure I should have changed that though because now the tv is not as stable, and I don't have the tools to reset it to factory specs.

[swamp_dude]

Hey man, thanks for sharing this. You mentioned you were able to make it work in a KV-20S90, which happens to be the one I own, would you mind going in a bit more detail about that since it has 2 composite inputs already? Thanks.

[matt]

Hey man, thanks for sharing this. You mentioned you were able to make it work in a KV-20S90, which happens to be the one I own, would you mind going in a bit more detail about that since it has 2 composite inputs already? Thanks.

Again, sorry I missed this post and didn't respond for a while.

The mod on the S90 should be the same as the one I documented for the S42. They have a nearly identical chassis.

However, you may want to skip the auto-switching part of the mod. I found out later that the voltage divider was pulling down the 9v power supply too much and causing the TV to turn off intermittently. I haven't taken the time yet to figure out the proper values yet. It'll work fine with a manual blanking switch.

[swamp_dude]

Hey man, thanks for sharing this. You mentioned you were able to make it work in a KV-20S90, which happens to be the one I own, would you mind going in a bit more detail about that since it has 2 composite inputs already? Thanks.

Again, sorry I missed this post and didn't respond for a while.

The mod on the S90 should be the same as the one I documented for the S42. They have a nearly identical chassis.

However, you may want to skip the auto-switching part of the mod. I found out later that the voltage divider was pulling down the 9v power supply too much and causing the TV to turn off intermittently. I haven't taken the time yet to figure out the proper values yet. It'll work fine with a manual blanking switch.

No problem man, I was planning on keeping it manual so I don't loose any inputs, but I hope you can figure it out, it came out really neat on the M42, and thanks again.

[KPackratt2k]

I recently got my hands on a Sony KV-27V20 TV (AA-2 Chassis) which I plan on modding for both RGB and YPbPr since this chassis has a YUV header for Picture-in-Picture (which is unused, but the header connector is kept intact for my TV). I was able to test the YUV blanking pin (using a 3x AA battery holder with a jumper wire in place of a third battery) and as it turns out the YUV is enabled, so no need to do some I2C modding, which is a good sign.

I was thinking about using a 3P3T slider switch to handle my Luma input as well as the blanking for both RGB and YPbPr inputs. I was wondering if this would be a good way to wire up my switch.

First Pole:
Pin 2 (Input): 5V Rail (through 470 ohm resistor, as recommended by RGB mods for this chassis.)
Pin 3 (2nd Output): YUV Blanking
Pin 4 (3rd Output): RGB Blanking

Second Pole:
Pin 2 (Input): Ground
Pin 3 (2nd Output): S-Video Sense Pin

Third Pole:
Pin 2 (Input): YUV Luma Pin
Pin 3 (2nd Output): S-Video Luma Pin

This is how I intend to make use my switch:
Position 1: Stock Composite/S-Video Inputs
Position 2: YPbPr Input
Position 3: RGB Input

How does this look? The reason why I'm not using the 3rd output of my switch for the RGB sync is that I intend to plug my RGB sync directly into the S-Video input, since I'm using RCA jacks for my RGB input just like my previous RGB mods. I wanted to make sure I got my switch plan right before I consider proceeding with this mod, just in case something is wrong with my current plan.

Don't worry about that KV-20EXR20 that I've mentioned earlier, I was confused by the serviceman label into thinking the shielded cage on the A board was the PIP hardware, turned out the PIP hardware is supposed to be on the P board which is only on the 27EXR25. I've ended up RGB modding that with its PIP header and will use a Retrotink COMP2RGB whenever I want to use a Component device on it (mostly my DVD player and Wii).

[me@danieldoyle.com]

I recently got my hands on a Sony KV-27V20 TV (AA-2 Chassis) which I plan on modding for both RGB and YPbPr since this chassis has a YUV header for Picture-in-Picture (which is unused, but the header connector is kept intact for my TV). I was able to test the YUV blanking pin (using a 3x AA battery holder with a jumper wire in place of a third battery) and as it turns out the YUV is enabled, so no need to do some I2C modding, which is a good sign.

I was thinking about using a 3P3T slider switch to handle my Luma input as well as the blanking for both RGB and YPbPr inputs. I was wondering if this would be a good way to wire up my switch.

First Pole:
Pin 2 (Input): 5V Rail (through 470 ohm resistor, as recommended by RGB mods for this chassis.)
Pin 3 (2nd Output): YUV Blanking
Pin 4 (3rd Output): RGB Blanking

Second Pole:
Pin 2 (Input): Ground
Pin 3 (2nd Output): S-Video Sense Pin

Third Pole:
Pin 2 (Input): YUV Luma Pin
Pin 3 (2nd Output): S-Video Luma Pin

This is how I intend to make use my switch:
Position 1: Stock Composite/S-Video Inputs
Position 2: YPbPr Input
Position 3: RGB Input

How does this look? The reason why I'm not using the 3rd output of my switch for the RGB sync is that I intend to plug my RGB sync directly into the S-Video input, since I'm using RCA jacks for my RGB input just like my previous RGB mods. I wanted to make sure I got my switch plan right before I consider proceeding with this mod, just in case something is wrong with my current plan.

Don't worry about that KV-20EXR20 that I've mentioned earlier, I was confused by the serviceman label into thinking the shielded cage on the A board was the PIP hardware, turned out the PIP hardware is supposed to be on the P board which is only on the 27EXR25. I've ended up RGB modding that with its PIP header and will use a Retrotink COMP2RGB whenever I want to use a Component device on it (mostly my DVD player and Wii).

Hey man,

I have a Sony KV-27V20 as well, what did you end up doing here? I want to figure out my options, I've never done a tv mod before. Thanks!
Dan

[KPackratt2k]

I finally got around to modding my KV-27V20 (AA-2 Chassis) for both RGB and YPbPr. While the RGB works as intended, I'm having a strange problem when blanking the YPbPr from the unused PIP header. It wasn't blanking with the 1000R resistor that was suggested by the BA-4 mod (I currently have a different resistor for each blanking line, so I'll change it so that both lines use a 470R), so I used the battery holder method of blanking it for testing and while it blanks now, there are weird blue and green lines on the sides of the screen.



Here's what I did differently from the last time:
- I've removed jumper resistors JR351 and JR352 along with capacitor C375 as the models that use the header didn't have them.
- I've added 0.47 uF capacitors to C360, C361, and C362 to match the models that had PIP.
- I've also added 220R resistors to R358, R359, and R360.

I've yet to actually test the input, so I don't know if this issue will manifest when a YPbPr signal is injected, but I'll wire up the jacks for that tomorrow to see if it does.

If anyone has any ideas on why this is happening and what I can do to fix it (in the event it does affect actual YPbPr usage), I'd appreciate it.

UPDATE: I tested it with an actual YPbPr signal by plugging my RGB jacks (I used RCA for all my RGB modded TVs) directly into the header and sure enough, it works properly. No weird lines or any distortions. I've even tested a Macrovision protected DVD with it on my Sony DVD player and it had no issues which means these YPbPr mods should be immune to Macrovision, unlike the RGB mods which can have issues with it since RGB never supported that in the first place (I assume this is why the PS2 can't play DVDs in RGB without hacking).

Still, I suppose this color lines effect is something you can expect when you activate the signal with nothing plugged in from my observation.

[matt]

Yes, that weird Chroma garbage is what you get if you enable YUV blanking with the input pins floating. On most models, they're tied to ground with a capacitor (that's what the jumpers & capacitors you removed were for). Once the mod is in place, the coupling capacitor and terminating resistor do the same thing.

[KPackratt2k]

How are you grounding your S-Video sensing circuit? I've tried grounding each of the pins that go to the S-Video shield on my UV board and it still won't sync. If I connect something to my S-Video input, it will sync. Do I have to go through one of the pins directly on the switching IC?

EDIT: Never mind, I was able to get it to sync by redoing the grounding wire on the top middle pin, where R233 is routed. I guess something must've been wrong with how I soldered the wire before.

[KPackratt2k]

The mod has been successful, as I've already mentioned in the RGB modding thread for those who have been following it. I'm also posting about it on this thread as suggested by its OP so that people who are more familiar with this one will also know about it.

https://imgur.com/a/BjLmET0

I have modded a Sony KV-27V20 (AA-2 chassis) to support both RGB and Component YPbPr via two different sets of color-coded RCA input jacks. I'm using a 3P3T slide switch to toggle between inputs. For RGB, I've performed the OSD mux mod documented by MarkOZLAD in the RGB mod thread. I did the Component mod using information from this thread and the service manual. The YUV input on the PIP header (unused in the model) was grounded by two jumper resistors (JR351 and JR352) and a capacitor (C375) which needed to be removed. R358, R359, and R360 had to be populated with 220 ohm resistors to serve as the inline resistors for the Component input. C360, C361, and C362 had to be populated with 0.47 uF capacitors as suggested by the service manual. The Luma (Y) had to be split into both the PIP header and the S-Video Luma line to sync. As suggested by an AA-2D RGB mod done by Osirus, I've wired the switch to ground R233 to force the S-Video input in YPbPr mode.