TV RGB mod thread

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KnuckleheadFlow
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Re: TV RGB mod thread

Post by KnuckleheadFlow »

Sorry about the length, but I’m pretty amped up about this and nobody understands why I’m all of a sudden obsessed with cutting up 15+ year old TVs! I need an outlet.
My brother and I only started considering an CRT RGB setup with Sony P/BVMs (or other similar monitors) in the last few months. Turns out we're late to the party and it seems almost impossible to get one (reasonably) in our area. Guys posting them on Kijiji get like 5 replies within 5 minutes. We'd pretty much given up when I happened upon this thread. This is really cool, I want to thank mikejmoffitt, tjsynkral and especially Voultar for their information.
My brother wanted a 20" to fit on his desk and at first I was going to work on his generic RCA before deciding to get a test TV in case I screw up. I picked up this Toshiba 20AF41C for a week ago Saturday, it turned out way better than the RCA and came with a DVD player. Checking the service menu, its powered on time listed in hex was 0E8E, a mere 3,726 hours!
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Using the service manual I found the OSD RGB lines and after a bit of continuity checking I plotted out the paths on the board and decided to desolder resistors R121, R122 and R123, attach the wires out to the switch from there and feed the RGB into the 0.1 µF caps C620, C621 and C622.
Micro:
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Jungle IC:
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Board wired up:
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The switch is kinda ugly, but it works. I was worried about interference with everything so close but in all the pictures I've seen of this no one else seems to care. Probably should've gone with DE-15 and VGA cables but decided to use BNCs because it's a ghetto BVM. It’s going RGB in, coax to switch where it's terminated with 75 O resistors. I soldered the shielding to the board for grounding and holding it in place, electrical tape for strain relief. The ends don’t budge so that’s good. OSD RGB comes into the top header pins, to the switch terminals over 4.7 kO resistors (replacing R121/2/3). Switch out goes out of the bottom header. 5v for blanking I got off the Jungle IC’s pin 2 to the blanking pin’s resistor. I left the blanking line untouched on account of the diodes. Sync is going into component Y. I’m thinking about feeding it directly to an IC, but I’m not sure where.
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So how’d it turn out? Pretty good, I’d say. This is from a model one Genesis, 75O and 220 µF inline on RGB and csync. The phone’s camera messes around with white balance and brightness, so it’s kind of hard to show what I’m seeing.
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The service menu has an “OSD horizontal” adjustment which I nudged a bit, but there’s a significant bit of cut off top and bottom. I don’t know if the vertical adjustment in the service menu will apply to the OSD but I’m adding a separate switch to the blanking line to see the game RGB with the service overlay, so I’ll see.
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Maybe it’s just my pickiness, but though it looks good but I think it can look better. I was always terrible at calibrating pictures, after a while of changing settings I can’t tell what looks good or bad anymore. It seems the colours are a little dull, too white? Not sharp enough? Maybe I was just expecting too much and this is as good as it gets. (Reds here are supposed to look redder, almost too red)
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So I’ve got four questions I’d like to throw out there:

I think Voultar mentioned a TV’s stock RGB decoupling capacitors might be insufficient. I’ve got some 1.5 µF SMT caps, maybe they’ll make it look better in place of the 0.1 µF?

Is there an advantage to running sync directly to an IC instead of using the Y component line, which seems ok horizontally? Should I put it in to pin 6 of the microprocessor? That pin is being fed from pin 33, sync out, on the Jungle IC.

I’m thinking of trying this on a TV with lots of horizontal lines, like the Sony P/BVMs have. Someone mentioned JVC’s 800 line AV-32Ds and I’m picking one up for $30 on Monday. The thing is, I’ll probably get rid of it after I modify it, since I’m looking to put something into my New Astro City. I’m willing to throw together a new bracket for the tube, but I think the 32” JVC will be just too big to fit without more modifications than I’m willing to do. Who knows if it’ll even compare favorably with the Nanao MS9 (which probably needs a cap kit anyway).
Anyone know of any other 800ish line TVs? I found references online to old articles from 1991 mentioning Panasonics with 800 lines but not much else and no one other than JVC advertised line count it seems. Are there other sources that list various TVs and more detailed specs?

Speaking of the NAC, am I correct in assuming this will also work well with JAMMA and MAME with an ArcadeVGA/JPAC?

Edit: Fixed giant images.
Edit 2: I put the 1.5 mic caps on last night before this post was approved. Yes, I do think they helped. To say the least!
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tjsynkral
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Re: TV RGB mod thread

Post by tjsynkral »

KnuckleheadFlow wrote:The switch is kinda ugly, but it works. I was worried about interference with everything so close but in all the pictures I've seen of this no one else seems to care. Probably should've gone with DE-15 and VGA cables but decided to use BNCs because it's a ghetto BVM.
A very good result! I personally prefer to install a SCART connector as the input method - I bet you're using a SCART to BNC adapter for all your games anyway. I get 2 SCART connectors really cheap from one of these: ebay.com/itm/281423387337

I also get the switches very cheap on eBay from China: ebay.com/itm/351705373445
KnuckleheadFlow wrote:The service menu has an “OSD horizontal” adjustment which I nudged a bit, but there’s a significant bit of cut off top and bottom. I don’t know if the vertical adjustment in the service menu will apply to the OSD but I’m adding a separate switch to the blanking line to see the game RGB with the service overlay, so I’ll see.
Usually the OSD is affected by all service adjustments. If you want less overscan on the vertical, you'd reduce v-size.

You mention PVMs and one thing I've been thinking of is doing this modification to a non-RGB supporting PVM such as the 20N5U.
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KnuckleheadFlow
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Re: TV RGB mod thread

Post by KnuckleheadFlow »

tjsynkral wrote:
KnuckleheadFlow wrote:The switch is kinda ugly, but it works. I was worried about interference with everything so close but in all the pictures I've seen of this no one else seems to care. Probably should've gone with DE-15 and VGA cables but decided to use BNCs because it's a ghetto BVM.
A very good result! I personally prefer to install a SCART connector as the input method - I bet you're using a SCART to BNC adapter for all your games anyway. I get 2 SCART connectors really cheap from one of these: ebay.com/itm/281423387337

I also get the switches very cheap on eBay from China: ebay.com/itm/351705373445
KnuckleheadFlow wrote:The service menu has an “OSD horizontal” adjustment which I nudged a bit, but there’s a significant bit of cut off top and bottom. I don’t know if the vertical adjustment in the service menu will apply to the OSD but I’m adding a separate switch to the blanking line to see the game RGB with the service overlay, so I’ll see.
Usually the OSD is affected by all service adjustments. If you want less overscan on the vertical, you'd reduce v-size.

You mention PVMs and one thing I've been thinking of is doing this modification to a non-RGB supporting PVM such as the 20N5U.
Funny you should mention that, I got into this whole thing looking to see if it's possible to add RGB to pro monitors that lack it. The JVC monitors were common without RGB and going for significantly less than Sonys. I hope modding the 800 TVL JVC or a good consumer Trinitron will be good enough for me. Hoping it'll be better than my Nanao at least.

And because I can't make things easy on myself, I'm going to make full coax cable with BNC connectors. I probably should change my mind on that, since a VGA cable is shielded enough, but I just love that BNC click. And I already bought most of the parts.
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FinalBaton
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Re: TV RGB mod thread

Post by FinalBaton »

The pics you posted look great Knuckle. ongrats :D
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Guspaz
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Re: TV RGB mod thread

Post by Guspaz »

tjsynkral wrote:You mention PVMs and one thing I've been thinking of is doing this modification to a non-RGB supporting PVM such as the 20N5U.
From what I've heard, the N5 should be even easier, since the board is the same as the N6: you remove a resistor to make the monitor think it's an N6, you add the missing components to the board which already has the unpopulated pads for them, you add some BNC connectors to the rear panel which might even already have holes for the missing connectors under the sticker (not clear on that), and do the same for the missing switch in the front...

It's not so much injecting RGB into a display that doesn't support it, as it is enabling functionality that's already there. As I've got a stack of N5Us at home, I wish that I had the knowledge to pull off such a thing myself, or knew somebody local who could do it.
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Re: TV RGB mod thread

Post by ENFORCER »

KnuckleheadFlow wrote:
Board wired up:
Image

The switch is kinda ugly, but it works. I was worried about interference with everything so close but in all the pictures I've seen of this no one else seems to care. Probably should've gone with DE-15 and VGA cables but decided to use BNCs because it's a ghetto BVM. It’s going RGB in, coax to switch where it's terminated with 75 O resistors. I soldered the shielding to the board for grounding and holding it in place, electrical tape for strain relief. The ends don’t budge so that’s good. OSD RGB comes into the top header pins, to the switch terminals over 4.7 kO resistors (replacing R121/2/3). Switch out goes out of the bottom header. 5v for blanking I got off the Jungle IC’s pin 2 to the blanking pin’s resistor. I left the blanking line untouched on account of the diodes. Sync is going into component Y. I’m thinking about feeding it directly to an IC, but I’m not sure where.
Its always nice to see people use polyimide tape with these circuit mods. :D
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Einzelherz
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Re: TV RGB mod thread

Post by Einzelherz »

Guspaz wrote:
tjsynkral wrote:You mention PVMs and one thing I've been thinking of is doing this modification to a non-RGB supporting PVM such as the 20N5U.
From what I've heard, the N5 should be even easier, since the board is the same as the N6: you remove a resistor to make the monitor think it's an N6, you add the missing components to the board which already has the unpopulated pads for them, you add some BNC connectors to the rear panel which might even already have holes for the missing connectors under the sticker (not clear on that), and do the same for the missing switch in the front...

It's not so much injecting RGB into a display that doesn't support it, as it is enabling functionality that's already there. As I've got a stack of N5Us at home, I wish that I had the knowledge to pull off such a thing myself, or knew somebody local who could do it.
How do you select the input channel?
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Guspaz
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Re: TV RGB mod thread

Post by Guspaz »

The contacts for the missing RGB input switch should still be on the motherboard, so you would simply wire up a switch to it. In fact, if the hole is already cut in the front panel and simply covered by the sticker, you could just cut a hole in the sticker and install a switch. If you've got spare N5 monitors, you could even harvest a switch from one of them. For example, I've got three of them, and when I picked them up, the guy at the TV station said that two of them were good, and one of them had a wonky picture.

EDIT: I'm pretty sure that the RGB input holes are present on the front of the N5 PVMs, it feels like there's no metal behind the sticker in those spots. Can't tell about the rear panel, though it seems like the TV station may have put an extra sticker overlay on top.
Last edited by Guspaz on Fri Jul 29, 2016 4:24 am, edited 1 time in total.
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mikejmoffitt
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Re: TV RGB mod thread

Post by mikejmoffitt »

I'm thinking we might be best off if I updated the OP with a summary, some useful links, a generalized schematic showing typical terminations, etc. Maybe I'll do this when I get home, or over the weekend.
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bobrocks95
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Re: TV RGB mod thread

Post by bobrocks95 »

mikejmoffitt wrote:I'm thinking we might be best off if I updated the OP with a summary, some useful links, a generalized schematic showing typical terminations, etc. Maybe I'll do this when I get home, or over the weekend.
That and maybe a list of TV's that people in the thread have modded or are known to have an RGB Jungle IC would be very helpful to newcomers.
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KnuckleheadFlow
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Re: TV RGB mod thread

Post by KnuckleheadFlow »

ENFORCER wrote:
Its always nice to see people use polyimide tape with these circuit mods. :D
Thanks. I bought some, might as well use it. That and kynar wire I find give mods that little extra touch.
mikejmoffitt wrote: I'm thinking we might be best off if I updated the OP with a summary, some useful links, a generalized schematic showing typical terminations, etc. Maybe I'll do this when I get home, or over the weekend.
I did have to absorb a bit before I felt ready to try it. It'd be also nice to know why some components work for some situations.

The only reason I went with the 1.5 µF caps was because I think Voultar told you to go from the 0.01 µF stock to 0.1 µF. Mine were 0.1 µF stock, so I just went up an order of magnitude. I know basically what a capacitor does, how here it's blocking off DC voltage, but I don't know what the 1.5 µF caps do to make the RGB input picture so much nicer while the OSD is fine 0.1 µF but makes the input RGB so... drab and disappointing.

I'd probably know if I hadn't forgotten so much from my college electronics classes but that how it goes.
tjsynkral
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Re: TV RGB mod thread

Post by tjsynkral »

Small update, I'm giving up on adding component to the 27S42 unless someone has any other ideas for me to try. I hooked up a THS7314 amplifier, and it made the picture brighter but still nowhere near as bright as it should be.
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suprcrackers
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Re: TV RGB mod thread

Post by suprcrackers »

tjsynkral wrote:Small update, I'm giving up on adding component to the 27S42 unless someone has any other ideas for me to try. I hooked up a THS7314 amplifier, and it made the picture brighter but still nowhere near as bright as it should be.
Sorry to hear that, man. I have a question on the KV-27FS13. Did you have to do any adjustments in Service Adjustment Mode? My blacks do not look right.

*edit* Yeah, I should probably try it out myself before asking. I didn't even have to go into the service menu. Carry on.
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Re: TV RGB mod thread

Post by ENFORCER »

Guspaz wrote:
tjsynkral wrote:You mention PVMs and one thing I've been thinking of is doing this modification to a non-RGB supporting PVM such as the 20N5U.
From what I've heard, the N5 should be even easier, since the board is the same as the N6: you remove a resistor to make the monitor think it's an N6, you add the missing components to the board which already has the unpopulated pads for them, you add some BNC connectors to the rear panel which might even already have holes for the missing connectors under the sticker (not clear on that), and do the same for the missing switch in the front...

It's not so much injecting RGB into a display that doesn't support it, as it is enabling functionality that's already there. As I've got a stack of N5Us at home, I wish that I had the knowledge to pull off such a thing myself, or knew somebody local who could do it.
I was planning on doing this mod to an N5 monitor myself. There was a local ebay auction for a 20N5U recently but it ended up going for way more then I wanted to spend on a monitor that needed further work to get it going. If I pick up one at some point, I want to do a walk-though on populating the board and enabling RGB functionality.
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Guspaz
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Re: TV RGB mod thread

Post by Guspaz »

I turned the N5s on last night: the convention I work for is next week, and I'm planning to lend/donate them to the videogame department to use for retro gaming (even if they don't do RGB, they're good monitors for composite/s-video consoles). I have three 14N5Us, so I did a basic calibration on them, getting the colour/contrast/geometry reasonably good on s-video. One of them is quite out of focus, but IIRC there's a pot somewhere inside for adjusting that?

Compared to my L2, they're pretty barebones. I really miss the L2's auto-calibration, where you feed it SMPTE colour bars and it automatically calibrates itself against that. Getting the phase/chroma/colour balance good is tricky when you have to just do it by eye and without an RGB input source. The N5's menus are all very minimalist, the service menu is a bit convoluted to use (but straightforward enough). The RGB input switch hole on the front of the monitor is definitely cut through the metal, I can feel the indentation under the button panel sticker. I assume the same is true about the missing RGB inputs on the back, but I couldn't tell.

I did find a full service manual, which helped: http://diagramas.diagramasde.com/otros/ ... 10-00e.pdf

Two random notes on the N5 (and probably N6) monitors, both of which applied to all three monitors that I have:

1) Composite is always much darker than s-video, and these monitors don't store per-input settings, so you can adjust for composite or s-video, but not both
2) s-video's phase is way off by default, pretty far into the green, but composite is fine. Turns out that by default there is a chroma band pass filter service menu setting that is enabled for composite but disabled for s-video. Enabling this setting fixes 75% of the problem, tweaking the phase offset in the service menu and/or the regular menu solve it completely. No idea why this setting is disabled for s-video by default, the image is plain wrong without it.

RGB doesn't have a phase setting, so that shouldn't be a problem if they're so modded, but RGB may suffer the same fate as the other inputs: if you calibrate it for the RGB input, then you may not be able to use composite/s-video, as they would look wrong.
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KnuckleheadFlow
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Re: TV RGB mod thread

Post by KnuckleheadFlow »

InfamousSabre wrote:The 24F650T uses the ITC008 chassis. It has a single TDA9567 video processing chip, so that means that there are no OSD RGB pins to tap into. However, the TDA9567 does have R/V G/Y B/U input pins which seem to already be properly terminated after coming onto the board through a header. It looks like I just need to plug right into that header and then tell the TV to use that input somehow. Any ideas?
It seems to me this schematic shows that TDA9567 (IV001) totally does have OSD RGB pins going in on pins 46, 47 and 48. Looks to be analogue too.

What I would want to do is cut the RGB coming out on BV001's pins 15, 11 and 7 (R, G and B, respectively), connect to a 4P2T switch (which would also have the console's RGB coming in) and add the switched output back in at the capacitors for pins 46, 47 and 48 (R, G, B) on IV001. As mentioned before, why cut traces when one can desolder resistors or jumpers (making sure to put equivalent resistors back in somewhere down the OSD line before the switch).

The switch would also output 5v to the blanking input, pin 45 on IV001. I don't see any diodes on the blanking line out of BV001, so I'd want the switch to switch between the 5v (when external RGB is active) and the output from pin 16 on BV001. For this, I'd see if I can remove resistor RV019 and feed the 5v from the switch to the solder pad on the pin side. I'd connect the line out of BV001's pin 16 (along with RV019 or an equivalent) onto the opposite solder pad.

The values on capacitors CV023, CV024 and CV025, 47nF, is about half of what I had on my TV (0.1 µF or 100 nF) and more than the 10nF on some of the Sonys. You'd probably have to replace those with a higher value, but I don't know what. I'd try... maybe 5 µF?

Of course, I'm no expert and I've only done this once, so if you do this and fry something, you've been warned. But I can more or less follow a schematic :)

Edit: actually, here's how I'd do it. Makes more sense than the way I did it on my TV, but I didn't know I was going to have to change the RGB decoupling caps. The OSD RGB should be fine going through the 1.5 µF caps but if it isn't, just put the old caps back in before the switch.

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mvsfan
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Re: TV RGB mod thread

Post by mvsfan »

I hope you figure that out, Guspaz. I have several RGB parts from a broken N6 that i kept.

If i could easily convert an 20N5u into an 20N6u using the parts i have here, I want to do that. The N5 is so much less expensive than the n6.
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suprcrackers
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Re: TV RGB mod thread

Post by suprcrackers »

You know what's frustrating? When you mod your second larger than 27" Trinitron, this time it was the KV-36FS13 and you are left with a great bright, sharp but flawed RGB picture. All of this is because the CSYNC fed to luma goes through some stupid post processing that delays the image a hair of a second. OH THE HUMANITY!!! THIS THING WEIGHS 200 POUNDS AND DOESN'T WORK RIGHT!!!
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Re: TV RGB mod thread

Post by tjsynkral »

suprcrackers wrote:You know what's frustrating? When you mod your second larger than 27" Trinitron, this time it was the KV-36FS13 and you are left with a great bright, sharp but flawed RGB picture. All of this is because the CSYNC fed to luma goes through some stupid post processing that delays the image a hair of a second. OH THE HUMANITY!!! THIS THING WEIGHS 200 POUNDS AND DOESN'T WORK RIGHT!!!
Can you post a picture of what you're seeing? That doesn't sound like a problem you would expect with CSYNC into luma.
I had some issues with interference and lag caused by using too much length of wire, and saw them improve (not totally go away) when I shortened it all up.
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suprcrackers
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Re: TV RGB mod thread

Post by suprcrackers »

I will post pictures tomorrow. I have it in the back of my Expedition. I'll have someone help me unload it tomorrow at my house. I actually needed a forklift to get it loaded and unloaded while I was alone in order to work on it in my shop.

I think it has to do with the 3D digital comb filter that these 2 large ( KV-36FS13 & KV-32FV15) Trinitrons use. My wire is about 16" in total (scart socket ---> switch ---> jungle. Both sets acted exactly the same. the 27" KV-27FS13 that you and I have done works perfectly, but uses a three-line digital comb filter instead. That's my theory anyway.
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suprcrackers
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Re: TV RGB mod thread

Post by suprcrackers »

I think you were right. I thought I was getting a good csync by grabbing it from pin 11 on the cxa1145 on the genesis. It turns out it needs to be terminated at 75 ohms and a 220uf cap on it. I did this and the ghosting greatly improved. It's barely noticeable now which could be from interference. Thanks.
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Re: TV RGB mod thread

Post by roush97 »

I've been reading about this RGB mod for a couple weeks now. I'm good with electronics and soldering, but have never messed with a CRT. I could use a little guidance. I'm attempting to add RGB to a JVC AV-27230. My Micon and Jungle IC chips seem nearly identical to KnuckleheadFlow's chips.

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However, I'm not sure where the blanking signal is. Also, my Micon RGB outs aren't labeled as OSD. Can anyone point me in the right direction? Is this TV not a good candidate? Any help would be greatly appreciated.

Thanks
Mike
Last edited by roush97 on Thu Aug 18, 2016 5:42 am, edited 2 times in total.
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suprcrackers
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Re: TV RGB mod thread

Post by suprcrackers »

Houston, I think we have a problem.

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xga
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Re: TV RGB mod thread

Post by xga »

Don't tell me that you've RGB modded all of those sets??? :shock:
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Re: TV RGB mod thread

Post by leonk »

I hope he's not in Houston, and I hope that's not open free space behind him! (You know what they say about Texas, open space, and guns!) :shock: :shock: :shock:
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suprcrackers
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Re: TV RGB mod thread

Post by suprcrackers »

A)Houston - No, you are safe, South Dakota.
B)Open Space and Guns - In my neck of the woods, that would be an affirmative.
C)No, only 6 have been RGB modded so far, I'm looking at downsizing. Half of these TV's are going to go bye-bye. The family and I took a trip down to KC this weekend with a trailer and picked up 11 mod ready Trinitrons and one mod ready Panasonic for a grand total of $5. The rest are from when I first started and just picked up whatever CRT I could get my hands on whether it could be modded or not.
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suprcrackers
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Re: TV RGB mod thread

Post by suprcrackers »

roush97 wrote:I've been reading about this RGB mod for a couple weeks now. I'm good with electronics and soldering, but have never messed with a CRT. I could use a little guidance. I'm attempting to add RGB to a JVC AV-27230. My Micon and Jungle IC chips seem nearly identical to KnuckleheadFlow's chips.

Image

Image

However, I'm not sure where the blanking signal is. Also, my Micon RGB outs aren't labeled as OSD. Can anyone point me in the right direction? Is this TV not a good candidate? Any help would be greatly appreciated.

Thanks
Mike
Image

The blanking pin is #19 on the TB1253AN followed by 20-22 for R, G ,and B respectively. They are just right for RGB at 0.7Vp-p.
roush97
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Re: TV RGB mod thread

Post by roush97 »

Thank you suprcrackers. That was my guess. I'm not sure on a couple of other things. Do I need to disconnect the original blanking signal or just add 5v? I'm going to pull sync from component (cmp_y2, pin 45 Jungle). Will that work? There is a capacitor inline on that input. Does it matter if I tap in before or after the cap? Do I need the 75 ohm resistors inline on my RGB input and 75 ohm resistors from each RGB line to ground? I really appreciate the help.
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Re: TV RGB mod thread

Post by knohbody »

Hello everyone,

I'm hoping someone can help me. I'm modding a Sanyo DS-13330 for RGB input.

I've tracked down the service manual, as well as the jungle IC datasheet. The datasheet is somewhat lacking. It has the pinouts, but not what the chip is expecting.

Datasheet: https://www.dropbox.com/s/edrve6bzjwk3a ... y.pdf?dl=0

Service manual: https://www.dropbox.com/s/j5nr6s918bc9h ... 0.pdf?dl=0

So far, I've removed the stock resistors on the chassis, wired in the R, G, and B lines with a 0.1 decoupling capacitor and terminated them with a 75 ohm resistor to ground. I've tied composite video/csync (depending on the system) to the video input on the chip, and wired a switch in to apply 5v to the blanking pin.

Everything works, but the video is very dim on the genesis (Model 1) that I'm using to test, to the point of only being able to see the brightest of colors, and slightly dim, and missing shades of colors on the super famicom I'm using. I have a strong feeling that this is due to the inputs not expecting 0.7 peak to peak voltage on the RGB lines. Page 25 in the service manual shows the RGB out from the chip, but nothing on the input that I can see. Any suggestions?
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suprcrackers
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Re: TV RGB mod thread

Post by suprcrackers »

Sorry it took so long to get back to you. Nothing beats working a 16 hour day. :? :(

I always disconnect the blanking signal and put it on a 4 pole double throw switch along with the RGB signals. I've never tried leaving it untouched and just applying 5v. It could work, but am not sure. I always pull luma (y) from the back of the (green) component plug itself or the back of the luma on svideo. It's just easier for me that way plus I'm already there for the left and right audio respectively. You just need 75 ohm resistors from each RGB line to ground not inline. If you have any other questions, let me know. Good luck.
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