TV RGB mod thread

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viletim
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Re: TV RGB mod thread

Post by viletim »

jwo825,

Be careful with old television sets that don't have any A/V inputs. Many of them have a live chassis. That means the ground of the TV set is not isolated from the mains power input. You can get an electric shock just from touching the set's ground while it's switched on. It's not a problem for normal operation because there's no exposed metal on these sets except for the RF connection, which is isolated. Live chassis power designs stopped being popular once AV inputs became standard as the cost of extra A/V isolation circuitry was greater than the cost of making a safe, isolated power supply.
jwo825
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Re: TV RGB mod thread

Post by jwo825 »

viletim wrote:jwo825,

Be careful with old television sets that don't have any A/V inputs. Many of them have a live chassis. That means the ground of the TV set is not isolated from the mains power input. You can get an electric shock just from touching the set's ground while it's switched on. It's not a problem for normal operation because there's no exposed metal on these sets except for the RF connection, which is isolated. Live chassis power designs stopped being popular once AV inputs became standard as the cost of extra A/V isolation circuitry was greater than the cost of making a safe, isolated power supply.
Thanks. Fortunately, I grew up in the CRT era and know all about the potential for electric shock. I made myself a discharge tool and made sure to discharge it and double check with the volt meter before going in there.
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KnuckleheadFlow
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Re: TV RGB mod thread

Post by KnuckleheadFlow »

I think I'm done with the board. It's pretty simple, I just did what the datasheets told me to do. But this being my first, there's probably a bunch of layout don'ts and I could probably keep tweaking it for who knows how long, but I think this will do for now. Those that know EE/PCB design, I'm open to any tips. I tried to make it look nice at least. It's small too; 45mm x 60mm, 1.77" x 2.36".

Image

Image

I was originally going to etch it myself, but I think I might get it done professionally. So I figured I'd ask if anyone here would be interested in getting in on that. I've got a day job, so I'm not looking to start a business here and everyone is free to make their own copy (guess I'll have to upload the files somewhere eventually).
I think it'd be under $10 a board. Additional parts are 12 (or 9) resistors, 6 capacitors, 3 ICs and an on-off switch. This comes to an additional $5-10, depending on where you buy it.
tjsynkral
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Re: TV RGB mod thread

Post by tjsynkral »

suprcrackers wrote:
tjsynkral wrote:In my experience with SNES, the very first models with the separate sound unit and S-ENC video chip put out very soft and drab RGB (as well as S) and barely worth upgrading that model from S to RGB. However, if you modify that model SNES with component output, the sharpness is fantastic and you get perfect square pixels. The only downside is the color temperature is noticeably different from RGB and other video outputs, so you'll be adjusting the color settings on your TV when you switch.

The SNES Jr provides great RGB with the RetroRGB board (I added S and CSYNC as well). It's not quite as sharp as the component mod for the S-ENC model but it's much better than the original and you don't have the calibration issues.

Side note, I don't have experience with the later SNES Phat 1-chip models.

So are you saying a component modded 1st gen SNES has a superior picture to a 1chip RGB modded SNES that uses a 7374? Or are you basing your findings of the old 7314s or off the standard stock RGB output with resistors to reduce the brightness?

I'm asking because on my 1chip I just took 750ohm resistors to ground and called it a day. I thought the picture looked pretty good compared to my old first gens RGB, but I have always wondered how a 7374 based solution would look in there. I really liked the results in had with my PC Engine using the 7374. Interested in doing a component mod to my first gen SNES too. Thanks.
I just said that I have no experience with the 1chip :D (Are you including the Jr. in your definition of 1chip? They're not the same thing.)
I think it's highly down to personal preference whether S-ENC or SNES Jr. RGB is better. They're both excellent, but I tend to favor the Jr. because I prefer hooking up with SCART and I don't need to re-adjust the color settings on my TV.

I still think the pixel edges are sharper with the component modded S-ENC SNES.
tjsynkral
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Re: TV RGB mod thread

Post by tjsynkral »

KnuckleheadFlow wrote:I think I'm done with the board. It's pretty simple, I just did what the datasheets told me to do. But this being my first, there's probably a bunch of layout don'ts and I could probably keep tweaking it for who knows how long, but I think this will do for now. Those that know EE/PCB design, I'm open to any tips. I tried to make it look nice at least. It's small too; 45mm x 60mm, 1.77" x 2.36".

I was originally going to etch it myself, but I think I might get it done professionally. So I figured I'd ask if anyone here would be interested in getting in on that. I've got a day job, so I'm not looking to start a business here and everyone is free to make their own copy (guess I'll have to upload the files somewhere eventually).
I think it'd be under $10 a board. Additional parts are 12 (or 9) resistors, 6 capacitors, 3 ICs and an on-off switch. This comes to an additional $5-10, depending on where you buy it.
It seems like a lot of wasted space to me - you could fit 2 boards in the same space if you made it more compact. You could also redesign it to eliminate the 3 links.
Why resistors on the output? I would want the RGB outputs to go through 0.1 or 0.01 caps and nothing else.
tjsynkral
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Re: TV RGB mod thread

Post by tjsynkral »

Pikkon wrote:Here's my component modded super fami running on my trinitron.

Image
It looks pretty nice, how did you wire yours? I ask because the way I wired mine up doesn't match any of the diagrams on the internet and I'm curious if you went with the internet plans or did your own thing.
lukilla
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Re: TV RGB mod thread

Post by lukilla »

Any people with osd mods could test this image please?, I wonder what ranges are you getting :

Image
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Voultar
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Re: TV RGB mod thread

Post by Voultar »

tjsynkral wrote:(Are you including the Jr. in your definition of 1chip? They're not the same thing.).
Yes, for all intents and purposes they are the same. The 1CHIP SNES and SNES Mini differ only any board routing and PCB size.
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KnuckleheadFlow
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Re: TV RGB mod thread

Post by KnuckleheadFlow »

tjsynkral wrote: It seems like a lot of wasted space to me - you could fit 2 boards in the same space if you made it more compact. You could also redesign it to eliminate the 3 links.
Why resistors on the output? I would want the RGB outputs to go through 0.1 or 0.01 caps and nothing else.
I'm not sure what you mean by 3 links.
The resistors on the output are there as specified by the LT1675 data sheet. It's an amplifier too with the output twice the input voltage and the data sheet mentions it needs to be terminated, with no caps added on the pins.

I laid it out with hand soldering in mind so I used relatively big 1206 components mostly and left the option to use headers on the input and output. I also wanted to have three resistors in line on the input for 0.5 Vpp TVs; for 0.7 they can be jumpered. I suppose I could have squeezed everything closer together at the cost of making assembly more annoying, but I don't think by half. Besides, I think it's already pretty compact frankly. It is after all only about the size of my two thumbs.
Last edited by KnuckleheadFlow on Wed May 03, 2017 11:03 pm, edited 1 time in total.
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suprcrackers
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Re: TV RGB mod thread

Post by suprcrackers »

Knuckleheadflow, I would be down for ordering a couple of those boards to try out.
Last edited by suprcrackers on Thu May 04, 2017 12:40 am, edited 1 time in total.
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Pikkon
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Re: TV RGB mod thread

Post by Pikkon »

tjsynkral wrote:
Pikkon wrote:Here's my component modded super fami running on my trinitron.

Image
It looks pretty nice, how did you wire yours? I ask because the way I wired mine up doesn't match any of the diagrams on the internet and I'm curious if you went with the internet plans or did your own thing.

Thanks,the board is a SNS-GPM-CPU-01 or 02.

All I did was add a 100uf cap to the Pr and Bp and for green I took it from pin 7 of the multi out and added a 100ohm,did a pal snes the same as well.

And I have done the SHVC-CPU-01 and I used this and it came out good.
https://gbatemp.net/attachments/comp-jpg.44482/
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KnuckleheadFlow
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Re: TV RGB mod thread

Post by KnuckleheadFlow »

tjsynkral, dude! You were so right. There was tons of wasted space.
I decided to throw out my ideas of how it should be spaced out and wanted to see how close I can make everything without any other considerations. About halfway through I realized it won't be that much harder to hand solder and that I like this layout way better. The board is now 42.5mm * 25mm, 1 2/3" * 1". That's less than 40% of the original area!

Image

Image
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buttersoft
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Re: TV RGB mod thread

Post by buttersoft »

KnuckleheadFlow wrote:
tjsynkral wrote: I also wanted to have three resistors in line on the input for 0.5 Vpp TVs
Out of interest, because I'm about to mod a 0.5Vpp input set, what should the value of those resistors be for a 0.7Vpp source?

The board is looking pretty nice!
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KnuckleheadFlow
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Re: TV RGB mod thread

Post by KnuckleheadFlow »

Thanks, I can't wait to actually have one.
When a TV has 0.7 Vpp OSD, that's the same as most RGB video sources and no voltage divider is needed; so 0 ohms.
Image

That's what I meant by jumpered. You could just put a wire across the pads, but if you're ordering other resistors already and they're 100 for $1.00...

E: And just to show how small it really is:
Image
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buttersoft
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Re: TV RGB mod thread

Post by buttersoft »

KnuckleheadFlow wrote:When a TV has 0.7 Vpp OSD, that's the same as most RGB video sources and no voltage divider is needed; so 0 ohms.
That's not what I wrote :)

I have a 0.7Vpp source, but the jungle IC takes the OSD at 0.5Vpp. I imagine a simple 2/5 ratio divider would do the trick. Assuming I just throw in a regular 75R termination to ground, that would make the missing resistor 30R...?
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KnuckleheadFlow
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Re: TV RGB mod thread

Post by KnuckleheadFlow »

buttersoft wrote:
KnuckleheadFlow wrote:When a TV has 0.7 Vpp OSD, that's the same as most RGB video sources and no voltage divider is needed; so 0 ohms.
That's not what I wrote :)

I have a 0.7Vpp source, but the jungle IC takes the OSD at 0.5Vpp. I imagine a simple 2/5 ratio divider would do the trick. Assuming I just throw in a regular 75R termination to ground, that would make the missing resistor 30R...?
Oops, misread that. Yes, 30 ohms for 0.5 V.
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buttersoft
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Re: TV RGB mod thread

Post by buttersoft »

Cheers for confirming :)
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buttersoft
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Re: TV RGB mod thread

Post by buttersoft »

So i'm having a problem with the chassis from a Teac CT-M5122H. The RGB is connected through IC101 pins 14-16, with pin 13 as blanking. It works fine, i haven't yet adjusted the levels, but the interference in the picture is really, really bad. I've tried disconnecting the OSD at R635-R638, reconnecting it, and a few other things. The picture is crawling with grey, almost horizontal lines that bow a bit in the middle. Removing R655-R658 seems to make the problem worse.

Service manual, with schematic on last page - https://track5.mixtape.moe/rnatkf.pdf

Any ideas?

(Note that the service manual contains a mistake - pin 16 of IC101 is not connected to the blanking line near R655-R658)

EDIT: I really need to try taking the input caps right out of circuit so nothing from the filter caps near the missing ICs 801 & 802 can interfere...? I'll try it and report back.

...Nope. Made the noise problem far, far worse. I'm going to have to think about this one, but any help would be much appreciated :)
lukilla
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Re: TV RGB mod thread

Post by lukilla »

Are you guys making sure your consoles are producing a standard video signal?, Tim mentioned it is critical:

http://members.optusnet.com.au/eviltim/ ... m#megamstr
MarkOZLAD
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Re: TV RGB mod thread

Post by MarkOZLAD »

Hey guys,

I have posted a new thread for my LG CA-20F80 that I have investigated RGB Scart modding. It turns out for certain LG chassis models you only need to replace the Composite jacks with a Scart jack for a simple mod that costs about 4 US Dollars and requires just some easy soldering and a change to the service menu.

http://shmups.system11.org/viewtopic.php?t=60010

I hope this is of interest,

Cheers,

MarkOZLAD
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MarkOZLAD
OSD/External RGB Mux Diagram
OSD/External RGB Mux Resistor Value Table 0.7Vp-p : 0.5Vp-p

"Imagine toggle switch OSD modding a TV in 2019" - maxtherabbit
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buttersoft
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Re: TV RGB mod thread

Post by buttersoft »

viletim wrote: The TDA8841 is a 56 pin DIP isn't it? Page 5 for pinout. R, G, B, into pins 23, 24, 25. 'Fast blanking' (RGB enable) into pin 26 (0.9 to 3.0 V). Page 15 of the datasheet mentions that fast blanking for RGB-1 is controlled by the IE1 bit in some internal register. If it's not set to 1 (active) then the blanking input isn't going to work. If this is the case then you'll need pull out the serial EEPROM connected to the micro and dump it. Compare the EEPROM dump to the register map on page 17. See if you can work out which byte contails the IE1 bit. If you're stuck try adjusting the colour saturation and reading it again.
I found a second, identical set, but am still having trouble. The register map doesn't correspond to the location the set is actually storing information on the EEPROM. I can adjust the colour saturation from 32 (50%) to B2 (50% with a leading 1), but nothing changes. And if I then change the saturation, to 51%, the byte resets the leading 1 to a 0, leaving a value of 33. I don't think the IE1 bit is where it's meant to be. I'd really love to be able to get into the service menu, but the remote batteries leaked and the traces are like grilled cheese. The cited service codes uses buttons this remote doesn't have, anyway.

Grrr. It's a nice tube again, but i can't think what to do next. I do get like a half-tone (is that right?) picture with the blanking pin set to 0.8V or so, i may not have tried that low a voltage before, but the picture is ghosted, dim, way off-colour and filled with noise - the same as the other set i was trying that's also EEPROM controlled (3 posts above this one). You can actually see the luma image in the background a little, I think. Only i can't find a half-tone mode setting as i don't have the remote :(
andre_retrogamer
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Re: TV RGB mod thread

Post by andre_retrogamer »

Hello, I'm following the post on mod osd on tv crt, I wonder if I'm on the right track. My tv Sony Trinitron 25" KV-25FS12B - JUGLE I/C CXA2135S

Image

Image

Image

I did! It worked out!!!!!!!!!!

Image
MarkOZLAD
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Re: TV RGB mod thread

Post by MarkOZLAD »

Hey all,

Have started a new thread here on a mod

http://shmups.system11.org/viewtopic.php?f=6&t=60130

Would be great if some experienced guys could have a look at it and provide some advice.

Cheers,

MarkOZLAD
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OSD/External RGB Mux Diagram
OSD/External RGB Mux Resistor Value Table 0.7Vp-p : 0.5Vp-p

"Imagine toggle switch OSD modding a TV in 2019" - maxtherabbit
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KnuckleheadFlow
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Re: TV RGB mod thread

Post by KnuckleheadFlow »

Like you mentioned in your post, (which I'll reply to here, just because), that CXA2130S can't be that much different than the other CXA2XXXes we've seen here, so like those it'll almost certainly be fine with standard 0.7 Vpp RGB. It even has has the 0.01 μF caps we've seen (which you should replace as others modding Sonys in this thread have).

About the blanking voltage, in most cases, if you don't exceed an IC's supply voltage (Vcc), you won't fry said IC. I don't remember what others have done for their Sony's blanking, but if the datasheets specify 1V for blanking (Ys), no need to mess around with a pot. Getting 5V down to 1V is as simple as a voltage divider using 1000Ω and 250Ω resistors.

Both the SCART connector's ground and the termination resistors need to be connected to the TV's ground. To be clear, we're always talking about digital, logic ground not earth ground (mains).

I can't tell from the picture what the connector's lead pitch is. I'm going to guess it's 2.54 mm as it's pretty common, but only way to be sure is to measure it. Unless it's listed in the parts section of the manual. Once you know the pitch, take your pick. Male headers, female sockets, it's up to you.
https://www.digikey.ca/short/3drhth
https://www.digikey.ca/short/3drh38
TylerL
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Re: TV RGB mod thread

Post by TylerL »

I wanted to say thank you for all the tips learned while lurking this thread, and show off my mod :D
After I was gifted a Sony KV20TR23, I looked up schematics for it online and was surprised to find that it has a (seemingly) rare daughterboard to handle closed captioning. This meant it has an awfully convenient socket on the main board with every necessary pin for analog RGB, fed directly to the Jungle chip. No soldering or board removal necessary!
Image

I spent a good amount of time on eBay and other sites looking for inexpensive SCART parts and accessories for my Genesis, SNES, Wii, and for VGA PC output. It seemed like EuroSCART was the best standard connector to work with.

This surface-mount SCART connector's pins look like they were meant for breadboard connectors...
Here, I've connected RGB along with their separate grounds, as well as the SCART shield ground itself.
Image

Pardon the breadboard mess. I plan to design and solder a nice compact module soon. Then again, I'm very lazy.
Image

Plugged right into the pins on the TV! Couldn't possibly be more convenient (unless, of course, this was a PAL60 TV in the first place...)
I've also tapped into YS and 5V to connect to my breadboard for activating blanking, and chassis ground as well connected to SCART shield ground.
Image

I found a SCART in-line "breakout" adapter that lets me tap into the Composite and Audio signals, which I feed into the traditional inputs on the back of the TV for Sync and Audio. (ignore the cable colors)
Image

Success! And somehow on the first try! Here's a video showing the complete setup, where I toggle the blanking pin high to provide a realtime example of the difference in quality on Sonic 2 through a model 1 Genesis.
https://www.youtube.com/watch?v=4yQHp0pbHMI

Later, I perfected a Linux-based KMS RetroArch install, which feeds a 3840x240 15KHz signal over VGA. Gorgeous and lag-free. For the first time in over a decade, I can play my favorite old fast-twitch and precision platformer games without an emulation delay driving me nuts. Seriously, I've barely been able to enjoy retro gaming before this setup. In fact, the latency is so low, I don't even feel the need for real hardware in most cases!
Image
I've never been an fan of emulator CRT shaders, but the image quality on these ancient games somehow looks high-def on a good Trinitron.

My only issue with the VGA connection is a strange white fringing around high-contrast lines. The checkerboard pattern in the 240p Test SNES ROM looks nearly solid white, for example. Strangely enough, if I pass the VGA single through my Extron (no processing, just passthrough!), the resulting image is perfect. Am I missing something additional that needs to be done (resistors, etc) to the signal? I'd rather cut the Extron our of the chain, obviously...especially since it doesn't really DO anything.

Again, thanks for the insight! If you have any questions or comments, please let me know!
Lebeauluc
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Re: TV RGB mod thread

Post by Lebeauluc »

Here is a quick update on my try to modify a toshiba 20AF43C. It was a total failure, it was the second time that I have been trying to mod the TV, but it seems that the digital jungle IC is quite problematic. On the first try I had a beautiful picture, but It was in the wrong color palette. So after this first failure, I said to myself that I should try feeding the sync on the luma from the S-Video input, it was way worst than before I had no stable picture with partial sync on a full black background.

I am listing the jumpers I used to do this mod, the only thing that change between the two tries was the video input and a couple of month:

R : W112
G : W108
B : W107
Vcc : W082
Fast Blank : W114
Luma (Sync) : W135

Is there anything wrong or this set is incapable of being RGB modded?
MarkOZLAD
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Re: TV RGB mod thread

Post by MarkOZLAD »

KnuckleheadFlow wrote:Like you mentioned in your post, (which I'll reply to here, just because), that CXA2130S can't be that much different than the other CXA2XXXes we've seen here, so like those it'll almost certainly be fine with standard 0.7 Vpp RGB. It even has has the 0.01 μF caps we've seen (which you should replace as others modding Sonys in this thread have).

About the blanking voltage, in most cases, if you don't exceed an IC's supply voltage (Vcc), you won't fry said IC. I don't remember what others have done for their Sony's blanking, but if the datasheets specify 1V for blanking (Ys), no need to mess around with a pot. Getting 5V down to 1V is as simple as a voltage divider using 1000Ω and 250Ω resistors.

Both the SCART connector's ground and the termination resistors need to be connected to the TV's ground. To be clear, we're always talking about digital, logic ground not earth ground (mains).

I can't tell from the picture what the connector's lead pitch is. I'm going to guess it's 2.54 mm as it's pretty common, but only way to be sure is to measure it. Unless it's listed in the parts section of the manual. Once you know the pitch, take your pick. Male headers, female sockets, it's up to you.
https://www.digikey.ca/short/3drhth
https://www.digikey.ca/short/3drh38


Greatly appreciate the reply. I had started my wiring and had the grounding incorrectly set up. Will revise tonight, shouldn't be too difficult.
___________________________________________________
MarkOZLAD
OSD/External RGB Mux Diagram
OSD/External RGB Mux Resistor Value Table 0.7Vp-p : 0.5Vp-p

"Imagine toggle switch OSD modding a TV in 2019" - maxtherabbit
fandangos
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Re: TV RGB mod thread

Post by fandangos »

Could someone elaborate on this: " Pull the jungle mixer blanking pin out of circuit, and tie it high (nearby jungle VCC, usually 3.3~5V) to make it always blanking (always showing RGB)"

My tv has a TB1230N, with analog RGB pins.
Schematics here:
http://html.alldatasheet.com/html-pdf/3 ... 230AN.html

I'm not sure which pin is the fast blank and how to wire it? I need to feed voltage to it, is that correct?
Dochartaigh
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Re: TV RGB mod thread

Post by Dochartaigh »

This has probably already been asked and answered, but I was wondering for TV's which have component input, is there much of a difference in picture quality between RGB modding that TV, and using the stock component inputs?

I wonder because when I switch between RGB SCART cables on my PS2 (think I tried this same comparison on my original Xbox at one point too), and the regular PS2 component cables (even on high-end BVM and PVM's), they honestly seem to be like 98% identical to each other (and that other 2% could just be wishful thinking).
leonk
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Re: TV RGB mod thread

Post by leonk »

Dochartaigh wrote:This has probably already been asked and answered, but I was wondering for TV's which have component input, is there much of a difference in picture quality between RGB modding that TV, and using the stock component inputs?

I wonder because when I switch between RGB SCART cables on my PS2 (think I tried this same comparison on my original Xbox at one point too), and the regular PS2 component cables (even on high-end BVM and PVM's), they honestly seem to be like 98% identical to each other (and that other 2% could just be wishful thinking).
On consumer CRT TV's, not that much. But then again, not all consoles output component! Especially the older ones ..
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