TV RGB mod thread

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titan91
Posts: 57
Joined: Sun May 14, 2023 1:44 pm

Re: TV RGB mod thread

Post by titan91 »

retrogamer47658 wrote:Alright, thanks! I'm working with a set that is also RF/mono only, I've gotten pretty far along with it except for the jailbar pattern when no source is plugged in and a sudden (temporary) brightness increase when using RGB.

Also, I've been looking over the datasheet for that IC you're talking about. You said something about a comb filter separating Y/C again, and I happened to come across this bit in the manual:

Image

Not entirely sure what all these values mean, but it seems like the comb filter can somehow be deactivated; that could, in theory, allow you to use s-video. If it helps, I enabled A/V on my set (Portland PT1301) by clipping one of the pins on the microcontroller; 5v on the pin activated the RF input and 0v activated A/V, so that was fairly simple to do. I will admit, there are a lot more service menu settings for this kind of stuff on your set than on my junky Portland, but the same concept could possibly apply in some way.

I have no idea what would cause other Sony products to not work with it though, sorry about that.
Your Portland set, is it a rebranded Philips? If so, do you have the service manual for it? I wasn't aware the comb filter could be turned off, interesting. What model of service manual did you get that screenshot from?
retrogamer47658
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Re: TV RGB mod thread

Post by retrogamer47658 »

is it a rebranded Philips? If so, do you have the service manual for it?
Nope sorry. It's a rebranded Daewoo, chassis CN-001A. If you would still like to see the service manual, it can be found here: https://elektrotanya.com/daewoo_chassis ... nload.html
What model of service manual did you get that screenshot from?
Actually, I found this in the same datasheet you had posted a little while back:
https://datasheetspdf.com/pdf-file/8705 ... TDA9587H/1

Really hope you can get this guy working, super interested to see how this will turn out!

Edit: fixed the link.
titan91
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Re: TV RGB mod thread

Post by titan91 »

Thanks for that info. Unfortunately the complexity goes up exponentially from here. Those are addresses used for the I²C data bus that the microprocessor uses to communicate with the rest of the peripheral components. That's way beyond my knowledge and ability.
retrogamer47658
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Re: TV RGB mod thread

Post by retrogamer47658 »

Ah, oh well. Dunno if you have a hot air station or anything, but if you could somehow desolder it and get an EEPROM reader then this could become a lot more feasible - I don't really see another way without reprogramming the IC. Even then, one would probably have to find another IC similar to this one that can be programmed, assuming the original one can't be. I would glady take a look at some of that stuff if you can get the code to me.

I have an EEPROM reader myself (which admittedly I haven't used much) but I can confidently say that it works very well. You can find it on amazon here:
https://www.amazon.com/gp/aw/d/B0BG8W7W ... asin_title
It comes with a bunch of adapters, one of which should hopefully fit your IC. The software is also very easy to use, I could easily walk you through that if you decide to go down this path.

I definitely still encourage you to play with settings and other stuff, could be totally possible without needing any of this!
titan91
Posts: 57
Joined: Sun May 14, 2023 1:44 pm

Re: TV RGB mod thread

Post by titan91 »

Actually, this chip does utilize an external EEPROM for its firmware:

https://www.veswin.com/product-24C16W6.html

Here it is on my chassis board.
Spoiler
Image
I also have an EEPROM reader. May try and dump an image of the chip next time I have this TV apart, if my alligator clips will fit. If I do I will share it but I don't expect to find anything we could make any sense out of. You would need two very similar TVs and would have to image both of the chips then compare in a hex editor.
retrogamer47658
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Re: TV RGB mod thread

Post by retrogamer47658 »

Alright, good to know that option is available as a last resort.

I did some more poking around in that datasheet, and I've been rereading prior progress updates as well. It sounds like you've been injecting video into pins 40, 42, and 44 (CVBS1, CVBS2, and CVBS3/Y respectively), as well as pin 45 for the chroma input. You could have seen this already, but pin 6 also seems to be of interest:

Image

It seems to be a copy of pin 5, something to do with LEDs, but pin 6 also has an optional composite video input. Not sure if pin 6 is currently connected to anything in its factory state, but maybe you could disconnect it from the trace and inject composite video there? Don't know which input it would even show up on, though it could be worth a shot to try. I'll keep looking and see if there's anything else that could be useful.

Edit: fixed the image
titan91
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Re: TV RGB mod thread

Post by titan91 »

At this point I have 2 video inputs connected anyway, so I don't need to tap into any more. I may stick with AV2 and FRONT if I get the tuner input working again, since AV1 overrides the tuner. If I can't get s-video by injecting luma into CVBS2 I may try it with CVBS1. But then again, it wouldn't be labeled as CVBS if they were designed to be used with s-video. The designated pins for Y/C don't work, so that's my logic. Yet, s-video is pretty much always assigned to AV1 on TVs that have an s-video input. So you would think Y/C would be shared with the CVBS1 pin.

Also, I just realized the firmware EEPROM is also I²C and not SPI. I have experience wth reading SPI EEPROMs, I²C is bidirectional. So I won't be attempting that, since it's a bit of a more obscure process plus I don't want to brick the microcontroller on the chassis if I have read/write set backwards for example.
PlunderBunny
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Joined: Fri May 26, 2023 6:02 am

Re: TV RGB mod thread

Post by PlunderBunny »

Hi all! I have an old Zenith B19A02D (Daewoo Chassis CN-001C) that I'm attempting to get some use out of with an RGB mod. This is the first RGB mod that I've done and with the help from this thread I think it's gone relatively smoothly so far! Following what other people have done in the thread and based on my needs, so far I have:

-Cut off the OSD RGB signal lines going from the micom into the LA76814 jungle chip on pins 14-16
-Set the blanking on pin 17 of the jungle chip to a permanent 5V
-Added BNC jacks for my RGB/Sync inputs to the back of the case
-Connected RGB to the jungle chip on the OSD signal pins, with signal terminated to ground through 75ohm resistors and with a 0.1uf cap between the source and chip to decouple
-Connected composite sync to the jungle chip on VIDEO INPUT (Y IN) pin 42 (TV doesn't have a composite video input, just RF, so can't use the method of dual composite video/RGB unfortunately)

I've had partial success after all this... I definitely get a visible signal, looks like the brightness be a bit low but I can troubleshoot that after solving the bigger problem: sync is aaaall screwy.

It seems like the TV is getting partial sync; vertically, the image will alternate between "locking in" and holding for maybe a couple seconds at a random phase, then rolling for maybe half a second, then repeating, all seemingly at random. Horizontally, the image mostly doesn't roll, but constantly wavers a small amount back and forth, occasionally rolling before "locking in" again. It seems like it's definitely getting SOME sync signal, because it's not just completely rolling and garbled, and more importantly, if I unplug the sync cable it gets worse, with the image constantly rolling horizontally and the erratic vertical rolling getting a little worse.

Anyone have any ideas of what could be causing that or how to diagnose/fix it?

Either way, wanted to say thank you for this awesome thread, tons of great info here!
KPackratt2k
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Location: Seattle, WA, USA

Re: TV RGB mod thread

Post by KPackratt2k »

Try wiring your sync like this, this is how it was done on another RF-only Zenith TV using the same jungle chip with good results.
labrat wrote:[Signal --->(75 ohm to GND)-->100 ohm-->2.2ufCap-->PIN42

I can now see the incoming composite, when selecting AUX input.
(tested with composite from a VCR, and then from an arduino)...
PlunderBunny
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Re: TV RGB mod thread

Post by PlunderBunny »

KPackratt2k wrote:Try wiring your sync like this, this is how it was done on another RF-only Zenith TV using the same jungle chip with good results.
Thanks! Tried searching through the thread for relevant posts but missed these. Went back and read through labrat's posts, makes sense that the CVBS would need some doctoring before sending it into the chip. I'll give this a try a little later today and edit this post with the results!
RebeL9
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Re: TV RGB mod thread

Post by RebeL9 »

I got this JVC TM600 field monitor. It’s in really good shape but I wonder if it’s possible to RGB mod it. Anyone tried?

Image
Image
PlunderBunny
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Re: TV RGB mod thread

Post by PlunderBunny »

Tried the [Signal--->(75 ohm to GNF)--->100ohm--->2.2uf Cap--->PIN42 layout connecting to my SNES's RGB cables, no improvement. Just like before, it seems like it's trying to sync with a not-quite-right signal it's getting but can't get all the way there.

Anyone have any other thoughts?
retrogamer47658
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Re: TV RGB mod thread

Post by retrogamer47658 »

Tried the [Signal--->(75 ohm to GNF)--->100ohm--->2.2uf Cap--->PIN42 layout connecting to my SNES's RGB cables, no improvement.
Does the schematic have any info on optional A/V inputs? It may call for a different cap/termination resistor on the video line. I was dealing with a similar issue on a different set, though much less severe; my sync itself was fine, just the brightness was bit wonky. The schematic said that the composite video line in should have a 10uF cap and 75 ohm termination, so I tried that and it fixed all of my issues. Don't really know too much about your set though, just a thought as to what could maybe be happening.
PlunderBunny
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Re: TV RGB mod thread

Post by PlunderBunny »

retrogamer47658 wrote:
Does the schematic have any info on optional A/V inputs? It may call for a different cap/termination resistor on the video line. I was dealing with a similar issue on a different set, though much less severe; my sync itself was fine, just the brightness was bit wonky. The schematic said that the composite video line in should have a 10uF cap and 75 ohm termination, so I tried that and it fixed all of my issues. Don't really know too much about your set though, just a thought as to what could maybe be happening.

SUCCESS! Well, mostly, at least... While I was looking at the optional A/V inputs as you recommended, I realized that the jungle chip had different input pins for CVBS over RF vs. from a standard RCA jack. I should have thought of that earlier! Since this TV doesn't have a composite jack (and I haven't done any further modifications to add one), I figured that the pin intended for a signal from the absent composite RCA jack might be completely shut off. I switched my composite signal over to pin 40 where the RF CVBS signal comes in, and boom, I have sync!

The only problem that I have now is that different scanlines waver horizontally, like the image it being viewed through rippling water. Link to image below, excuse the angle, my CRT is in a bit of an awkward position on my workbench. The effect is the most visible in the FX Pak Pro logo in that image, it's supposed to be a smooth curve all along that edge.

https://imgur.com/a/oVa5DRm

The lines aren't static, they occur all over the image and rapidly waver back and forth a short horizontal distance. Anyone encounter this before and manage to solve it, or have any ideas on what it might be?
retrogamer47658
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Re: TV RGB mod thread

Post by retrogamer47658 »

Anyone encounter this before and manage to solve it, or have any ideas on what it might be?
Funny enough, I think I actually encountered a similar issue on my RF-only set too. I would recommend playing with the brightness a little, using the 240p test suite - both on a grid and color bars. Excessive brightness can cause some weird geometry issues, especially horizontally. On my set (before I added the 10uF cap), brighter colors would cause greater distortion, particularly when the brightness was very high.

If fiddling with the brightness doesn't change anything, the only other thing I can think of is to bump up the 2.2uF to something a little higher. Hope this helps!
PlunderBunny
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Re: TV RGB mod thread

Post by PlunderBunny »

Success again!!!

I broke out the oscilloscope to take a look at the signal on the CVBS there I had it feeding into the RF in pin on the jungle chip and noticed that, when the TV was on, the signal got REAL noisy and hot, so I figured there was some interference coming in somewhere along the RF channel. So I just cut the line from the RF jack and boom, perfect beautifully clean sync.

https://imgur.com/a/LsEBj8N

There are only two remaining issues:

1. When there are bright colors on a darker background, there is a VERY noticeable dark band smearing to the right from the brighter area. You can see it best in my images on the picture with the dialogue box, look off to the right in the sky after the box on the same scanlines as the text. I've looked around about that before and seen people suggesting that that may be an issue with capacitance on the video signal line. Currently I've just got 1uf ceramic caps feeding into the RGB input on the jungle, think changing those for different values of caps would help?

2. BIG band of distortion at the top of the screen, this is very evident on the image with the purple lamp post things. This honestly bothers me less than the smearing, I could live with this much more easily than that problem. I didn't get 240p Test Suite images, but otherwise the geometry looks surprisingly good! At least to my eyes.
retrogamer47658
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Re: TV RGB mod thread

Post by retrogamer47658 »

PlunderBunny wrote:Currently I've just got 1uf ceramic caps feeding into the RGB input on the jungle, think changing those for different values of caps would help?
I would start with adjusting the brightness pot on the flyback transformer, as that's the easiest thing to do. You can also try adjusting contrast, preferably in the service menu but the user menu should be fine as well. If neither of these change anything, then I would look towards the 2.2uF capacitor on the sync line - not the RGB lines. I'm not sure what you would replace it with should this be the case, so you may just have to do a little experimenting.
PlunderBunny wrote:BIG band of distortion at the top of the screen, this is very evident on the image with the purple lamp post things.
This is also likely a brightness/contrast issue, as it's much more similar to the issues I experienced. I strongly recommend getting the 240p test suite, it's super helpful for diagnosing issues like this and is a great tool to have down the road for calibration stuff. You can download it for free if you have a Wii, specifically a homebrewed one. If you have a Wii but don't know how to homebrew it, you can find a lot of good tutorials online - it's really easy to do (and also free!).
PlunderBunny
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Re: TV RGB mod thread

Post by PlunderBunny »

retrogamer47658 wrote: I would start with adjusting the brightness pot on the flyback transformer, as that's the easiest thing to do. You can also try adjusting contrast, preferably in the service menu but the user menu should be fine as well. If neither of these change anything, then I would look towards the 2.2uF capacitor on the sync line - not the RGB lines. I'm not sure what you would replace it with should this be the case, so you may just have to do a little experimenting.
I've got a 2.2uf cap on the sync line already, 0.1uf caps are on the RGB lines currently. I'll fiddle with the brightness/contrast and see where that gets me, thank you!
retrogamer47658 wrote: This is also likely a brightness/contrast issue, as it's much more similar to the issues I experienced. I strongly recommend getting the 240p test suite, it's super helpful for diagnosing issues like this and is a great tool to have down the road for calibration stuff. You can download it for free if you have a Wii, specifically a homebrewed one. If you have a Wii but don't know how to homebrew it, you can find a lot of good tutorials online - it's really easy to do (and also free!).
I've got 240p test suite and was looking at it already! :D I just forgot to get a picture of it and didn't wanna turn it on and take pictures of the test suite since my roommates and I have not gotten sucked in by playing Firmament :lol: I'll try adjusting brightness and contrast and report back on where that gets me!
PlunderBunny
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Re: TV RGB mod thread

Post by PlunderBunny »

Fiddled with the brightness and contrast settings in the service menu, adjusted them all over, they didn't have any effect on the smearing. Ditto for the screen pot on the flyback transformer, couldn't eliminate the smearing with any kind of adjustment.

https://imgur.com/a/ubnHgXL

I haven't tried changing out the cap on the sync line yet for other values, but... I don't quite get what the logic of that would be? The only thing that should be relevant on that line is the sync signal, I don't understand why that would ever contribute to that kind of smearing that I'm seeing. But I am by no means anything CLOSE to an expert, so if you can explain why that might be the culprit, please do! :D

After doing a bit more looking around, I've seen some people saying that this problem is indicative of a failing high voltage cap in the screen bias circuit. Here's a video of a guy repairing just such a problem.

https://youtu.be/ebOmWYqlOIY

My TV isn't getting that same absolute washing out of the image that this one is exhibiting, but the smearing going on is the same sort of thing, so I think I'm gonna look down this path.

The warping at the top of the image seems to have gone away, though! Dunno how that happened but I'll take it.
retrogamer47658
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Re: TV RGB mod thread

Post by retrogamer47658 »

PlunderBunny wrote:I haven't tried changing out the cap on the sync line yet for other values, but... I don't quite get what the logic of that would be? The only thing that should be relevant on that line is the sync signal, I don't understand why that would ever contribute to that kind of smearing that I'm seeing. But I am by no means anything CLOSE to an expert, so if you can explain why that might be the culprit, please do! :D
I'm flattered, but I'm by no means any kind of expert - I was just frustrated by the lack of info when modding my RF only set, so I'm glad that I can help out others trying to do the same. :)

Anyway, in my experience, video-related effects like these were only related to the sync line because of the fact that it was connected to a (composite) video input; basically meaning that however the jungle "interprets" the video, something was clearly not right with the video being injected. Your case could be a little different, especially depending on how you cut the line from the RF input. I've seen people discuss isolating that signal from the tuner (possibly page 141?), which seems to be different from just cutting it entirely. Don't know if that would really cause any smearing like that, but I would check if the antenna input has that smearing as well. If it doesn't, then I doubt a failing high voltage cap would be the cause.

On a side note, about the caps on the RGB lines, I've never actually seen what problems would indicate incorrect values... I'm guessing something along the lines of messed up colors? But probably nothing to do w/ "effects" like the smearing. Could be completely wrong, but hopefully this helps.
PlunderBunny
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Re: TV RGB mod thread

Post by PlunderBunny »

retrogamer47658 wrote: Anyway, in my experience, video-related effects like these were only related to the sync line because of the fact that it was connected to a (composite) video input; basically meaning that however the jungle "interprets" the video, something was clearly not right with the video being injected. Your case could be a little different, especially depending on how you cut the line from the RF input. I've seen people discuss isolating that signal from the tuner (possibly page 141?), which seems to be different from just cutting it entirely. Don't know if that would really cause any smearing like that, but I would check if the antenna input has that smearing as well. If it doesn't, then I doubt a failing high voltage cap would be the cause.
Fair enough, that could be the case, that something about the composite video on the sync line is interfering with the RGB signal... the hijacked OSD blanking SHOULD be completely overwriting the composite video signal, as I understand, but I don't know that for certain so I figure it's worth a shot...

Well, I just came back to my computer after getting rid of the actual composite video signal on that line.I ran the composite/sync line through a sync stripper and hooked it up to my oscilloscope just to double-check that there's no video signal, just the sync, and I can guarantee that there's nothing on that line but the sync signal. Plugged it into the TV and... no dice, still tons of smearing. So I think I can be sure that it's not anything with the composite video signal coming in itself over that line.

So at this point I think it's either gotta be a failing cap as I mentioned before, or something intrinsic to trying to put the sync signal in over the RF in pin, as I'm doing, rather than the composite RCA jack pin, which I tried before and couldn't get working because it seems to possibly be disabled.

retrogamer, you said you RGB modded an RF only TV like mine, do you happen to remember what jungle chip your TV has, and what input is designated for the pin you put your sync signal in on?
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evilsim
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Re: TV RGB mod thread

Post by evilsim »

Syntax wrote: Update
Ok so I figured out the bloody thing.
Sony CXA2139S 
Around 3v or more to the ext blanking pin turns on RGB.
Yet again Syntax your efforts have helped me to do a very fast turnaround on an ebay pickup today. TY SIR. :mrgreen: (its the same as Sony sets I've RGB modded years ago, but its been a while since doing one, so your comments helped me to prepare for the mod).

Sony KV-PF14P10 cute little flat 14" trinitron, with only composite and mono audio input(s). Service Manual says its a BG-3S board, it has a CXA2139S jungle as Syntax said.

Has my fav CN307 row of pins on the mainboard.
Found a 5v pin elsewhere on the board. 5v -> BLK pin on CN307 enables fast blanking (menus are washed out when blanking is on, volume, brightness etc etc).
Connect your 0.7v pp signals to CN307 R G B. Enjoy! I also twisted the FOCUS knob a tiny bit to get the picture a bit sharper/better.
The "VIDEO 1" displayed on this TV disappears a few seconds after the monitor catches sync (composite or RGB sync), but yes pressing the DISPLAY button on the remote also makes it go away (any sony TV remote will do it normally).
TV happily takes CVBS for sync or CSYNC TTL or CSYNC-75 (tested with a PC-Engine and a SNES).
retrogamer47658
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Re: TV RGB mod thread

Post by retrogamer47658 »

PlunderBunny wrote:you said you RGB modded an RF only TV like mine, do you happen to remember what jungle chip your TV has, and what input is designated for the pin you put your sync signal in on?
Just a quick note before I answer your question - I completely forgot that you're using BNC connectors and not SCART, starting to realize why what I said before didn't make any sense. Duh!

I don't remember the jungle chip specifically, but I do recall my set being a Daewoo Chassis CN-001A. I went the opposite route that you're going; I enabled composite (labeled as the LINE) input and wired my sync to the unused composite video in pin on the jungle (42?). Turns out, pin 1 on the microcontroller controlled the active input through a very simple 5v or 0v. 5v = TV and 0v = LINE, so I just clipped the pin to switch to 0v and LINE was enabled.

I was, however, using a SCART connector for my mod, and also added RCA jacks by connecting them to the audio/sync pins on the SCART connector. This is what I was talking about earlier with the 10uF cap and 75 ohm termination - without them, brightness would fluctuate and the LINE input screen would be a mess when nothing was plugged in.

It seems like using the tuner's CVBS input for sync has worked for people before. I tried to do that with my set but ultimately just gave up and went for enabling composite input. I'll do a little reading later and see how others managed to do it.
PlunderBunny
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Re: TV RGB mod thread

Post by PlunderBunny »

retrogamer47658 wrote:
Turns out, pin 1 on the microcontroller controlled the active input through a very simple 5v or 0v. 5v = TV and 0v = LINE, so I just clipped the pin to switch to 0v and LINE was enabled.

I was, however, using a SCART connector for my mod, and also added RCA jacks by connecting them to the audio/sync pins on the SCART connector. This is what I was talking about earlier with the 10uF cap and 75 ohm termination - without them, brightness would fluctuate and the LINE input screen would be a mess when nothing was plugged in.
Ahhhh gotcha, that makes sense, thank you!!! I've been thinking about trying to enable the composite input but hadn't seen how it was done, I can't believe I missed that "TV ONLY" pin on the microcontroller! I'll set up a switch there as well and see if inputting on the straight CVBS pin rather than the tuner's CVBS pin helps anything.
PlunderBunny
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Re: TV RGB mod thread

Post by PlunderBunny »

Dropped pin 1 to 0V to enable line and put the signal in over the pin for RCA jack CVBS, no dice. Still getting the severe smearing. :/ So unless someone gives me reason to believe it's something on the RGB lines themselves that might be causing this (maybe adding an in-line resistor, different cap value than .1uf?), I'm going to assume it's a failing high-voltage cap and move from there. Which would be a shame, as I don't have any high-voltage caps handy, none of them look bad, and I don't really have any good way to test them.
PlunderBunny
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Re: TV RGB mod thread

Post by PlunderBunny »

Just a note with some more info: The smearing effect seems to show the inverse color as the bright area, i.e. a bright red area seems to leave a cyan smear and vice versa. You can see this more clearly in this picture I just took.

https://imgur.com/a/lM6BVqp

Dunno if that gives anyone any ideas, but it's more info at least!
LandisSeralian
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Re: TV RGB mod thread

Post by LandisSeralian »

I was pointed here from reddit. I recently saved this RCA F35100ST from the trash and I'm looking to RGB mod it seeing as it only has RF, composite, and S-Video input. While S-Video is fine, if this TV is compatible with RGB mods that would be the best option. Ideally I'd like to mod it with Component rather than standard RGB but either works for me.
Image
Image

Unfortunately I've been having a lot of trouble locating schematics or the service manual for this TV online anywhere. I also don't feel comfortable opening this up without having done my research first as it is my only CRT at the moment. If anyone has any experience with this model or similar models or can point me in the direction of documentation it would be greatly appreciated. Thank you for your consideration.
retrogamer47658
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Re: TV RGB mod thread

Post by retrogamer47658 »

PlunderBunny wrote:Still getting the severe smearing. :/ So unless someone gives me reason to believe it's something on the RGB lines themselves that might be causing this (maybe adding an in-line resistor, different cap value than .1uf?), I'm going to assume it's a failing high-voltage cap and move from there.
Just to clarify, have you tested the antenna input after doing the mod? If the smearing does not occur on the antenna input, that would probably indicate something is up with the RGB lines (as you suspected). If smearing is present on both RGB and antenna input, then I would suspect a failing high-voltage cap.

Also, in your original post, you said you "cut off the OSD RGB signal lines going from the micom into the LA76814 jungle chip on pins 14-16". When you say cut off, do you mean disconnected the RGB pins on the jungle from their traces? There are a bunch of other factory components on the RGB lines, maybe that's why your colors are acting up a bit. This may not affect anything though, I'm only used to modding via muxing so I'm not familiar with the method of just clipping the OSD RGB lines entirely.

Outside of that, maybe try playing with service menu settings related to RGB? Kinda guessing at this point, honestly not too sure what else could be happening.
PlunderBunny
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Re: TV RGB mod thread

Post by PlunderBunny »

retrogamer47658 wrote:
Just to clarify, have you tested the antenna input after doing the mod? If the smearing does not occur on the antenna input, that would probably indicate something is up with the RGB lines (as you suspected). If smearing is present on both RGB and antenna input, then I would suspect a failing high-voltage cap.

Also, in your original post, you said you "cut off the OSD RGB signal lines going from the micom into the LA76814 jungle chip on pins 14-16". When you say cut off, do you mean disconnected the RGB pins on the jungle from their traces? There are a bunch of other factory components on the RGB lines, maybe that's why your colors are acting up a bit. This may not affect anything though, I'm only used to modding via muxing so I'm not familiar with the method of just clipping the OSD RGB lines entirely.

Outside of that, maybe try playing with service menu settings related to RGB? Kinda guessing at this point, honestly not too sure what else could be happening.
I haven't tested the antenna input after the mod, I did test it beforehand. I think there was some smearing, but I don't remember for sure, especially because I wasn't really looking for quality from the picture, just making sure things worked. I'll test it when I get a chance!

As for components between the OSD pins on the microcontroller and RGB input on the jungle chip...

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RGB into the jungle chip

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RGB out of the microcontroller

The OSD RGB signal from the microcontroller terminates through a 100pf cap, then goes through a 1kohm inline resistor, then terminates through another 1kohm resistor before going through a .1uf cap and into the RGB input on the jungle chip... as far as I can tell from the schematic, and I've checked a few times, those are the only components between the OSD RGB and jungle chip. I cut the OSD RGB leads coming from the microcontroller, I have the console RGB output terminating through 75ohm, running through a .1uf cap, then going straight into the RGB input pins on the jungle chip.
alimadhi
Posts: 27
Joined: Sun Jan 26, 2014 12:53 pm

Re: TV RGB mod thread

Post by alimadhi »

just finished RGB mod (MVC-19HR 19″ Hi-Res Color Monitor OSD)
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all looks good but only one proplem the edges bleeding color to right. can someone guess where is the problem?
its before the mod same the proplem
I appreciate you

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