TV RGB mod thread

[mvsfan]

Its mostly because broadcast monitors are expensive. Not only that, but large 4:3 broadcast monitors are almost always real old and tough to find.

Tvs you can often get them for free, and often, you will get similar results when you are talking about the large pvms. Tvs are also much newer.

most large 4:3 pvms never really had a high TVL.

[Shoryukev]

Its mostly because broadcast monitors are expensive. Not only that, but large 4:3 broadcast monitors are almost always real old and tough to find.

Tvs you can often get them for free, and often, you will get similar results when you are talking about the large pvms. Tvs are also much newer.

most large 4:3 pvms never really had a high TVL.

This is all true, I've been thinking of RGB modding my 32" sony trinitron for this reason. Ideally I'd go with a large PVM or NEC XM29 or something, but it seems easier to find bigfoot than one of those LOL

[FinalBaton]

Yep. As MVS fan said.

Some comsumer tubes are actually of very respectable quality, and some also have a very respectable TVL count. Coupled with an RGB input they make for a very fine CRT display. Plus you won't have to drop a couple undred bucks for it, as consumer CRTs are pratically given away nowadays. And you won't have trouble finding a consumer CRT either (pro CRT monitors can be quite hard to find).

For my part I really encourage this hobby, I think it's awesome that people go through with this! Have I not lucked out on a big quality RGB monitor for a cheap price, I would probably be looking at RGB-modding a consumer Trinitron with a Microblack tube right now.

[KnuckleheadFlow]

All broadcast monitors are hard to find in my area (Toronto), let alone a good one. By the time I'd see the ad, it'd be sold. Also, some people like the smaller screens and that's cool, but not me. The few larger screened monitors I've found have been too expensive for a 20+ year old screen of unknown hours. For $30 or whatever, I'm willing to roll the dice.
A big plus is that I also think it's really fun and stimulating figuring this out. It's a creative outlet for me and I'm learning a lot as I go along.

Thinking about the TVL count on the monitors vs something like the 800 TVL on the bigger JVC D series got me wondering about the feasibility of taking one of those HD CRTs with like 1000 TVL or whatever and bypassing all the digital circuitry. Wouldn't they have to be analogue at some point? Maybe even adapting some other chassis to drive it. You may have a bunch of black glass on the sides, but that's why there're bezels.

[mvsfan]

I have one of those Jvcs. i think Its comparable to a PVM-14N6U in picture quality. Very good to excellent. price was $25.

except the 1 i have is yuv only.

[KnuckleheadFlow]

Only yuv huh? I think we know what you have to do...

[Einzelherz]

I'm pretty sure he means it's YUV internally.

[KnuckleheadFlow]

Arrg of course. It's been a long day.

[Ed Oscuro]

All broadcast monitors are hard to find in my area (Toronto), let alone a good one.

Some guys in Toronoto were trying to sell a HD Igegami a while back...for like $5K US. Seems like it's no longer up, though.

[tjstogy]

In about 1999 we got a top of the line 32" Sony wega. N64 looked incredible, even in composite. That's a tv I'd consider RGB modding. My 20" pvm is wonderful, but I've been spoiled with the 32" size. You can't sit across the room with this pvm once you've been spoiled by the 32" size (and gotten plenty used to it).

[KnuckleheadFlow]

In about 1999 we got a top of the line 32" Sony wega. N64 looked incredible, even in composite. That's a tv I'd consider RGB modding. My 20" pvm is wonderful, but I've been spoiled with the 32" size. You can't sit across the room with this pvm once you've been spoiled by the 32" size (and gotten plenty used to it).

Well, get the model number, find a service manual and see if it's do-able. Dude, you could have near-pvm quality, on a 32" screen (maybe, don't quote me on that).

[Shoryukev]

Do you guys think it's worthwhile RGB modding my Sony KV-32S42? It has a great picture for only having s-video in it's stock form.

I have done lots of electronics projects (building guitar amps, modding consoles, installing ceiling fans around the house, etc.), so I'm not really afraid of doing it once the tube and large capacitors are properly discharged

Looking at the service manual, the signal sent to the tube is RGB, so it looks like it can be done as long as I research where I'm supposed to add connections to it.

[KnuckleheadFlow]

I found a manual for KV-32S42. On page 44 of the manual (page 28 in the PDF) it shows the the jungle IC (the CXA20955 labeled IC351) taking in OSD RGB on pins 16, 17 and 18, with blanking on pin 15. Looks like you're good to go. The caps are 0.01 microF so you'll need set it up like OP's Trinitron earlier on in the thread.

[Shoryukev]

Yep there it is, but what's blanking? Is that where I need to apply 5v to switch the OSD on manually so the RGB signal passes through?

Spoiler

I've been reading through the thread this afternoon, looks like for csync I need to wire it to the luma connection on the s-video input, and for sync on luma I need to wire it to the composite video input. I might use BNC connectors since I already have a SCART to BNC breakout cable and it would allow me to pysically swap between connectors for different types of sync. All I need is a BNC/RCA adapter, and I'll make my own adapter for wiring it to the luma pin on the s-video.

A SCART connector on the TV might be more convenient if I can figure out how to wire up both sync types and switch between them though.

I'll draw something up at work monday and post it to make sure I'm on the right track

EDIT: changed the picture to be a "spoiler" to not clutter the thread

[KnuckleheadFlow]

Yep there it is, but what's blanking? Is that where I need to apply 5v to switch the OSD on manually so the RGB signal passes through?



I've been reading through the thread this afternoon, looks like for csync I need to wire it to the luma connection on the s-video input, and for sync on luma I need to wire it to the composite video input. I might use BNC connectors since I already have a SCART to BNC breakout cable and it would allow me to pysically swap between connectors for different types of sync. All I need is a BNC/RCA adapter, and I'll make my own adapter for wiring it to the luma pin on the s-video.

A SCART connector on the TV might be more convenient if I can figure out how to wire up both sync types and switch between them though.

I'll draw something up at work monday and post it to make sure I'm on the right track

Right on. I recommend markertek.com for BNCs and accessories. Good prices on stuff you'll know will be 75 ohms, free fast shipping. They've got these nice bright colour coded BNC jacks I just got too. E: These ones.

Edit: blanking is YS or YM. Connect the line going in there to your switch along with the OSD RGB. It's a signal that'll blank the screen during each horizontal line's pass just for the time it takes to make a box or whatever for the OSD. So when you feed it 5v DC, it'll just have it black the entire pass and thus a black screen for our RGB.

[leonk]

forget the BNC connector. buy a cheap SCART pannel mount (female I believe) port on ebay.

[Shoryukev]

Here's what I have so far. I've decided to go with a SCART connector as long as my sync switch idea works.

Spoiler

From what I've read CSYNC needs to be connected to the luma pin on s-video, and sync on luma needs to be connected to the composite video input. The problem with my television is that it uses the ground connection on the s-video input to disable the composite video input.....so I added a DPDT switch that I'm hoping will allow me to choose. I need Csync for most situations (NESRGB, SNES, Genesis, Master System, etc.), but my Sega Saturn uses Luma Sync, and I've read my N64 will most likely use Luma Sync when I get it RGB modded.

I'm not sure where to get the 5 volts for the blanking yet. I still have more research to do before I order components and take apart the TV. The voltage on the switching pin on the SCART seems to vary, so I'm not sure if I can use that pin.

The connections on the inputs on the back of the TV will be on the inside of the panel. For the RGB connected to the jungle IC I'm going to solder them to the leg on the capacitors near it to avoid soldering to the pins on the IC. For the blanking pin I might have to solder directly to it if I can't find a component nearby to solder to. From looking at the schematics on the service manual I know the jungle IC is on the "A" board, hopefully it's easy to physically find it once I'm ready to install this mod.

What do you guys think of what I've come up with so far? It looks like it will be a little bit of a hassle, do you think this will be worth it versus just searching craigslist for another trinitron with component video and getting one of those RGB to YUV converter boxes?

EDIT: Changed the picture to be a spoiler to not clutter the thread

[KnuckleheadFlow]

Here's what I have so far. I've decided to go with a SCART connector as long as my sync switch idea works.



From what I've read CSYNC needs to be connected to the luma pin on s-video, and sync on luma needs to be connected to the composite video input. The problem with my television is that it uses the ground connection on the s-video input to disable the composite video input.....so I added a DPDT switch that I'm hoping will allow me to choose. I need Csync for most situations (NESRGB, SNES, Genesis, Master System, etc.), but my Sega Saturn uses Luma Sync, and I've read my N64 will most likely use Luma Sync when I get it RGB modded.

I'm not sure where to get the 5 volts for the blanking yet. I still have more research to do before I order components and take apart the TV. The voltage on the switching pin on the SCART seems to vary, so I'm not sure if I can use that pin.

The connections on the inputs on the back of the TV will be on the inside of the panel. For the RGB connected to the jungle IC I'm going to solder them to the leg on the capacitors near it to avoid soldering to the pins on the IC. For the blanking pin I might have to solder directly to it if I can't find a component nearby to solder to. From looking at the schematics on the service manual I know the jungle IC is on the "A" board, hopefully it's easy to physically find it once I'm ready to install this mod.

What do you guys think of what I've come up with so far? It looks like it will be a little bit of a hassle, do you think this will be worth it versus just searching craigslist for another trinitron with component video and getting one of those RGB to YUV converter boxes?

I don't know about luma sync, but you can connect csync to any input and it should sych the rgb when you switch to that input. For example, I'm using csync for both Genesis and SNES, connected to the luma component input. Some TVs might be weird, but that's how it's supposed to work. The RGB we're feeding bypasses any composite filtering the TV may have, making the sync signal a little out of sync with the image, causing the picture to be shifted to the left a little on some TVs. Connecting sync (raw csync or sync on composite video) to either the svideo or component luma avoids this.

Is your Saturn PAL? Because if it's NTSC it'll have csync on pin 1. I bought some Saturn 10 pin mini DIN connectors on ebay and I'll be using pin 1 for sync.


For the blanking I just attached a wire to the 5v input on the jungle IC to the switch. From the switch, I wired it to the jungle IC side of the last resistor before the blanking pin (this resistor goes to ground). Unlike the wires for the RGB and sync signals, the 5v wire can be as long as you need it to be, within reason of course.

Like OP, you'll probably have to replace the C363, 364 and 365 for a higher capacitance (I think 0.1µF worked for him). Probably easiest to desolder them and put the replacement higher value ones on a board after the switch. So both your external and OSD RGB would go through them before going back to the jungle IC side pad the original caps were on.
From this:

Code: Select all

OSD RGB -> C363/4/5 -> jungle IC pins 16-17

To this:

Code: Select all

OSD RGB -> bare C363/4/5 pad MCU side -> 4P2T swtich (external RGB) -> new 0.1µF (?) caps -> bare C363/4/5 pad jungle IC side -> jungle IC pins 16-17

To avoid feeding the 5v into the MCU blank pin, if there's a resistor in series on the blanking line between the MCU and jungle IC, desolder it and connect the switch between those pads, replacing the resistor before the switch this time.

Code: Select all

OSD blank -> some series resistor -> jungle IC blanking pin

To this:

Code: Select all

OSD blank -> some series resistor's bare pad MCU side -> same resistor (or equal value) -> 4P2T swtich (5v from somewhere) -> bare pad jungle IC side-> jungle IC blanking pin

And fuck converter boxes. When all goes well, this mod is really simple and the actual wiring doesn't take long at all.

[Shoryukev]

First of all, thanks for taking the time to explain this stuff to me!

I think I have what you just said correct for the most part, I made some quick changes to my schematic (I'll make it pretty later). I need to find where 5v is coming into the jungle IC, but I want to make sure I have the concept right first. Please feel free to let me know if I misinterpreted anything.

Spoiler

My saturn is a model 2 NTSC-US unit. When I bought my scart cable for it on ebay from retro_console_accessories I was warned that some model 2 saturns have problems with csync so I chickened out and went with sync on luma. I think my idea of switching between the luma pin on s-video and composite video will work....but if not I'll deal with it and just use c-sync wired to the luma pin on the s-video. Even if it doesn't work I should be able to just leave the switch in the position headed to the luma pin on the s-video and it's ground (for csync systems)....right?

The mod itself is cheap (I think I'm up to $13 not including wire for my list of stuff to buy), and I can pre-assemble/solder up the majority of it before opening up the case to the TV. I have small children in the house and I need the case to only be open for a night while they sleep so I'll do as much work as I can before opening it up.

EDIT: Make picture spoiler to remove clutter

[KnuckleheadFlow]

Sorry, your picture didn't originally load for me, so I didn't know you had it all laid out. Looks good. The thing about the luma is, I'm not sure if there's a need for the extra work of using different sync inputs is all. If composite can pick out the sync from a luma signal, I don't know why the S Video luma input couldn't. Of course, I have not tried a system that outputs sync on luma so I could be totally wrong.

And revising the capacitors like you did is good too. There's no point to having two sets of caps when feeding the OSD RGB through the higher value ones will work just fine. The SMD caps C363-365 are not polarized so I think they would've sent AC back the other way as well. I don't know if this will really cause a problem at such low voltage, in fact I doubt it would, but it doesn't hurt to avoid it.

As far as opening it up, The TV's PCB should slide right out easily once disconnected. No issue with then closing it back up to work at your own pace. And maybe show the kids what's inside. Spark their imagination and all that.

[Shoryukev]

The thing about the luma is, I'm not sure if there's a need for the extra work of using different sync inputs is all. If composite can pick out the sync from a luma signal, I don't know why the S Video luma input couldn't. Of course, I have not tried a system that outputs sync on luma so I could be totally wrong.

I'm not sure I fully understand it either, but here's what I think is happening. The luma pin on the s-video carries the luma and the sync....when you feed it csync it is an incomplete signal as far as the TV trying to display something from the s-video port.....but it does get the sync signal. The problem with feeding it a sync on luma signal is I think it would try to display it since it has both luma and sync.....so you send it to the composite video signal so once again it's an incomplete signal it can get sync from, but not enough there to try and display it.

Once again I could be totally wrong about this, but that's how I think it works. It could end up being more hassle than it's worth though....I haven't seen anyone else even give thought to the issue LOL. Maybe sync on luma does work through the s-video luma pin and I'm just overthinking it.

[KnuckleheadFlow]

Well it won't hurt to try I guess. There's idiosyncrasies to these things so who knows.

Shame you went with scart though. I was hoping there'd at least be someone else who prefers the satisfying click of connecting a BNC. But I get that it does make sense for convenience and cost.

[Shoryukev]

It would actually simplify things quite a bit if I went BNC. They are super easy to solder to, and I could just physically plug into the audio and sync connections externally instead of hacking it all up on the inside. I could just buy an RCA>BNC adapter to try my sync on luma idea, and build an adapter that plugs into the s-video on the back and has the luma and ground connected to a BNC on the other end.

I already have a SCART>BNC breakout cable I use with my 14" PVM, it might make my life easier if I went the BNC route. That and until I get a SCART switch it would make swapping systems easier since the BNC breakout cable is 3ft long, so I could get to it without having to pull the TV away from the wall.

[Shoryukev]

I think I underestimated how much easier going BNC would be. I redrew it for a BNC connection, and just look at how much less work is required! Assuming my schematic is correct of course lol

I already have a breakout cable, so the only thing I have to adapt would be going from the sync BNC to the correct pins on the s-video....but that's easy-peasy. I think I'm going BNC, if for nothing else than to not have to solder all the audio and sync connections to PCB mounted connectors on the inside. This way I can just plug it in externally and be done.

[KnuckleheadFlow]

That's right man, this is (North) America! Le Syndicat des Constructeurs d'Appareils Radiorécepteurs et Téléviseurs n'a aucune juridiction ici! Freedom Plugs!

[FinalBaton]

That's right man, this is (North) America! Le Syndicat des Constructeurs d'Appareils Radiorécepteurs et Téléviseurs n'a aucune juridiction ici! Freedom Plugs!

lol

[bobrocks95]

Yeah no need to go SCART here in the US unless you already have a bunch of SCART cables for consoles. BNC or VGA switches are MUCH cheaper and easier to come by.

[mikejmoffitt]

Vouching once more for going VGA for RGB. Keep audio out of those video cables! VGA cables are cheap and plentiful, and usually well shielded.

[Shoryukev]

Well I ordered all the parts I need. Should be here in a week or two (some of it is coming from china). What gauge wire should I use when I wire this up???

75 ohm 1/4watt metal film resistors
.1uf 50v ceramic capacitors
4PDT switches
chassis mount female BNC connectors
female BNC to RCA adapter

I'm going to cut up an s-video cable I have lying around and make my own BNC to s-video luma pin connection for csync. I'm excited about this project!!! Even if it doesn't look as good as my PVM-14N6U, it's a 32" monster of a CRT so it'll be worth it!

That's right man, this is (North) America! Le Syndicat des Constructeurs d'Appareils Radiorécepteurs et Téléviseurs n'a aucune juridiction ici! Freedom Plugs!

LOL!!! I thought of another reason I need sync on luma to work by the way....I have a PS1 and PS2 I want to get/make an RGB cable for soon, and they both have to use sync on luma for RGB.

Yeah no need to go SCART here in the US unless you already have a bunch of SCART cables for consoles. BNC or VGA switches are MUCH cheaper and easier to come by.

I do have SCART cables for 3 systems so far, but I have a BNC breakout for my 14" PVM so I might as well use that since wiring the BNC's is easier.

Vouching once more for going VGA for RGB. Keep audio out of those video cables! VGA cables are cheap and plentiful, and usually well shielded.

I agree with you on that, switchers are WAY cheaper! Not having to mess with the audio when doing the mod is a big factor too!

[mvsfan]

when your done with your tv it should look similar to the 14N6U. it will essentially be an RGB monitor.

Actually, at only 500 TVL, the 14N6U is the closest to a consumer tv of the Pvms.

I have one, and it does look similar, albeit a little bit sharper because of the aperature grille technology.