TV RGB mod thread

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TheRetromancer
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Re: TV RGB mod thread

Post by TheRetromancer »

theangryamoeba wrote:I recently trash picked a Sanyo DS24425. It's a got nice bright tube and all of the inputs that i thought I would need. Composite, S-video and Component. Then I read about RGB.

I was able to find the service manual for the set, but i'm not seeing any RGB lines that I can tap. Can someone else take a look at this and let me know if I'm missing something obvious?

https://drive.google.com/file/d/10zmhRo ... sp=sharing
According to the Schematics you provide, your RGB lines are pins 12, 13, and 14 on the IC801 chip. You have to zoom in on the very last page (pg 32).

On further inspection, it doesn't look like IC801 has RGB IN, but it does have RGB OUT that is pulled from the 'Video Matrix', which looks like it takes YPbPr and (encodes?) it to RGB before directly shooting it to a trio of transistors (Q721, Q711, and Q701) immediately before the actual screen itself. You might be able to interpose a properly adjusted RGB signal either before or after those transistors.
"Thanks for the nice reply. I do offer to do work without hot glue too if people prefer it that way." - Drakon
MarkOZLAD
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Re: TV RGB mod thread

Post by MarkOZLAD »

It’s a no go for RGB mod.
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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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Kabal2X
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Re: TV RGB mod thread

Post by Kabal2X »

Nice! Another Pelco monitor owner. I own the same exact model, S-video looks amazing, I assume RGB has to be fantastic. Had any luck trying the RGB mod on your set?
Thanks
SNK-NEO-GEO wrote:Hello guys.. complete newbie to mod.. Syntax helped me with the newbie questions over PM...

I am looking to RGB MOD my Pelco monitors.. Bellow are pictures of one of the units chassis and the one that i will be using for testing (the screen has a scratch, F-up during shipping on this one).. I would like to use SCART on the monitors.. Please take a look at the pictures and let me know what is the best to go about it...If rising the legs on the RGB-in line on the jungle chip is best or somewhere else..


Pelco PMC21A TDA8842 S1
https://drive.google.com/drive/folders/ ... IzzBQ1kdBq

"All you need is 75R resistors and 100n caps and your done.

3 wires RGBS with resistors to ground and caps inline
1 wire blanking with resistor to ground
1 wire sync
2 wires audio
1 wire ground. "
TheRetromancer
Posts: 116
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Re: TV RGB mod thread

Post by TheRetromancer »

EDIT2: I'm picking up a free KV-27V42 tomorrow. Does anyone know if the RGB1 input can be used? I know RGB2 is used for the service menu, but I'm not finding anything on enabling RGB1.

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"Thanks for the nice reply. I do offer to do work without hot glue too if people prefer it that way." - Drakon
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suprcrackers
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Re: TV RGB mod thread

Post by suprcrackers »

RGB1 is a no go.
Vermifuge
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Re: TV RGB mod thread

Post by Vermifuge »

RGB Mod RCA F25645 / CTC-203AX Chassis (Help Please)

I'm trying to sort out how to RGB mod this RCA F25645 CRT. It uses a CTC203XA Chassis. I noticed one other forum member boded a CTC-203 but not many notes on the subject. The problem I'm running into is this chassis is using a GemStar card and how it interfaces with the Jungle iC.

Here are some of my notes so far. It's not a lot. I'm sort of new to reading these circuit diagrams so please excuse any mistakes interpreting this.

https://imgur.com/a/6RovAik

My questions so far:
  • 1. Should I be tapping into the RGB before or after the gem star card? I assume after
    2. Is the FSW (Fast Switch) the same as banking? Where should I hijack the blanking signal?
    3. I think i see +5v coming off of a transistor? Q14115.
    4. For sync am i literally just plugins my sync cable into the composite input?
For interrupting the RGB I think I am looking at the 3 470 ohm resistors i marked in the diagram. There are also 3 .022 microfarad capacitors that i plaice are part of the same circuit. However 1. there are located on the back of the board and 2. They are SMD packages,

If someone could help me put a plan together for this mod it would be very appreciated.

Some of the images in the imgur link are taken from the GE 27GT720TX1 service manual. It uses the same CTC-203AX Chassis ge_27gt720tx1_ch_ctc203ax.pdf
Im also using the RCA CTC-203 Chassis Training manual to break down the different circuits. also pictured in the image link rca_chassis_ctc203_training_manual.pdf

I'm sure you guys are sick of answering the same question over and over. Please know i really have done my best to review and compile the available information. I have reached the limit of my ability to precede forward. so any advice is greatly appreciated.

Thanks for any input.
Last edited by Vermifuge on Thu Jan 09, 2020 9:47 pm, edited 2 times in total.
Hishimura
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Joined: Mon Jan 06, 2020 5:05 am

Re: TV RGB mod thread

Post by Hishimura »

Noob here have a Sharp 13N-M150B
link to service manual https://elektrotanya.com/sharp_13n-m100 ... nload.html
I know I am a noob but reading the schematic I do see RGB lines going from microcontroller to jungle chip and pulling apart the T.V and reading the schematic can confirm they are two separate chips, any help on determining resistor values or caps needed? Intention is RGB component for a N64
accskyman
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Joined: Tue Jan 07, 2020 1:38 am

Re: TV RGB mod thread

Post by accskyman »

Scratch this post, I2C chip and this tv is a most likely a bust. Back to searching for something.
Last edited by accskyman on Fri Jan 10, 2020 9:43 pm, edited 1 time in total.
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vol.2
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Re: TV RGB mod thread

Post by vol.2 »

Looking into this set for an RGB mod and wondering if someone could please check it out?
It looks to me that the RGB inputs on the jungle IC are only hooked up to Red and Green. Blue seems to be NC out of the Character IC and the blue input is tied to ground through a 1uF capacitor. (pin 19, C903)

Toshiba CX1467

here's the on screen interface chip

Image


Here where the signal comes out of the character generator for the on screen menu.

Image

This is the Character Gen pin output, showing the RGB outs on pins 12, 13, 14:
Image

Here is the pinout descriptions of the char gen chip:
Spoiler
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This is from the datasheet of the on screen interface, block diagram and example circuit:
Spoiler
ImageImage
MiteWiseacre
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Joined: Tue Jan 07, 2020 4:32 pm

Re: TV RGB mod thread

Post by MiteWiseacre »

Hello, new guy here. Read most of this thread and watched a bunch of videos and now attempting a mod.

Diamond Vision DTV2822, made in China I think it’s a Mitsubishi, I think it’s the same as many cheap house-brand TVs from mid 2000’s (cannot remember when I bought it but think 2008)
These are the data sheets I found that match most closely:

M37150M8-111FB (the osd chip)
https://html.alldatasheet.com/html-pdf/ ... XXXFP.html
M61266 (Jungle Chip) and the closest I’ve found:
https://html.alldatasheet.com/html-pdf/ ... 283FP.html

I’m outputting from my Mame machine which is running crt-emudriver and groovymame 15htz on VGA
The blue signal, for example, runs from pin#36 to 110ohm R to 0.1uF cap to pin #21
I’ve injected rgb between the resistor and the cap, disconnected the resistor to break the line.
Attached the H&V sync to a pot then to composite in, if I dial it down I get a nice stable picture.
5v to blanking, I can take this down to around 2.5v with a pot before it cuts out, makes no difference to the picture.
I’ve tried 75ohm to ground on rgb but that kills picture entirely, tried 1uf caps in-line no noticeable affect. It seems the signal is only like 0.25v coming from my vga Too low?

Problem I’m having is that I seem to only get red blue green and yellow, lots of black, it’s as if the colours aren’t mixing. Any suggestions? Am I inserting in the right spot?
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Syntax
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Re: TV RGB mod thread

Post by Syntax »

Last pic. 21 18 15 11 are your injection points.
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vol.2
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Re: TV RGB mod thread

Post by vol.2 »

Syntax wrote:Last pic. 21 18 15 11 are your injection points.
Thanks. Is there anything I need to consider that it says "B-Y, R-Y, G-Y?" That would make me think I somehow have to subtract luma from the RGB lines?


Edit: I thought that I was supposed to use the OSD inputs, and that they would correspond to R^TX, B^TX, G^TX, (or 21,18,15 + pin 12 for the blanking).

Perhaps I'm a little behind the times with this and it's better to use the TV RGB inputs to the jungle IC? If that's the case, I still am not completely sure about the "-Y" for the inputs on the TV out. I suppose I could figure out a circuit that does that, but if the TX inputs will work, maybe that's the way to go with this one?

I just saw your reply. Yeah, your probably right. I'll solder ahead.
Last edited by vol.2 on Wed Jan 08, 2020 5:52 pm, edited 2 times in total.
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Syntax
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Re: TV RGB mod thread

Post by Syntax »

Youre overthinking things now.

Just wire up the set and worry when you actually run into an issue.

Currently modding this little 12v portable color TV.

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Cursed Lemon
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Re: TV RGB mod thread

Post by Cursed Lemon »

Hi everyone! New face and mod newbie here. I saw 8-Bit Guy's videos on the RGB mods he made and got inspired, so I followed the link. I would love to get some guidance/advice on how to perform this mod, I have an inkling to turn an old CRT into my own RetroPie-driven arcade cabinet and the extra clarity from an RGB signal would be awfully nice. I just need some pointers! I'm a very handy guy but direct tinkering with a PCB is something I'm mostly green to.

What I'm working with presently is a Magnavox 20MT133S: https://www.p4c.philips.com/files/2/20m ... fu_aen.pdf

Unfortunately, a direct schematic for the television doesn't seem to be available online. However, there does seem to be a generic service manual I found that appears to reference the exact same board: https://www.eserviceinfo.com/downloadsm ... MT133.html

The microcontroller is a Mitsubishi M37272M6H: https://pdf1.alldatasheet.com/datasheet ... 72M6H.html

The video chip is a Mitsubishi M61203CFP: https://pdf1.alldatasheet.com/datasheet ... 03CFP.html

Bottom of the board: https://i.imgur.com/6oLrSrr.jpg

Top of the board: https://i.imgur.com/NsM3XVc.jpg

Any other info, just ask. Is this CRT eligible, or do I have to hack apart one of my flatscreen CRTs? :B
Vermifuge
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Joined: Sun Jan 05, 2020 8:25 pm

Re: TV RGB mod thread

Post by Vermifuge »

Syntax wrote:Youre overthinking things now.

Just wire up the set and worry when you actually run into an issue.

Currently modding this little 12v portable color TV.
The system I am working on is in a very cramped space. Accessing the main board and fooling around isn't exactly plug & play. I would prefer to get it right the first time.

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MarkOZLAD
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Re: TV RGB mod thread

Post by MarkOZLAD »

Vermifuge wrote:RGB Mod RCA F25645 / CTC-203AX Chassis (Help Please)

I'm trying to sort out how to RGB mod this RCA F25645 CRT. It uses a CTC203XA Chassis. I noticed one other forum member boded a CTC-203 but not many notes on the subject. The problem I'm running into is this chassis is using a GemStar card and how it interfaces with the Jungle iC.

Here are some of my notes so far. It's not a lot. I'm sort of new to reading these circuit diagrams so please excuse any mistakes interpreting this.

https://imgur.com/a/6RovAik

My questions so far:
  • 1. Should I be tapping into the RGB before or after the gem star card? I assume after
    2. Is the FSW (Fast Switch) the same as banking? Where should I hijack the blanking signal?
    3. I think i see +5v coming off of a transistor? Q14115.
    4. For sync am i literally just plugins my sync cable into the composite input?
For interrupting the RGB I think I am looking at the 3 470 ohm resistors i marked in the diagram. There are also 3 .022 microfarad capacitors that i plaice are part of the same circuit. However 1. there are located on the back of the board and 2. They are SMD packages,

If someone could help me put a plan together for this mod it would be very appreciated.

Some of the images in the imgur link are taken from the GE 27GT720TX1 service manual. It uses the same CTC-203AX Chassis ge_27gt720tx1_ch_ctc203ax.pdf
Im also using the RCA CTC-203 Chassis Training manual to break down the different circuits. also pictured in the image link rca_chassis_ctc203_training_manual.pdf

I'm sure you guys are sick of answering the same question over and over. Please know i really have done my best to review and compile the available information. I have reached the limit of my ability to precede forward. so any advice is greatly appreciated.

Thanks for any input.

I would be looking to use an OSD mux method. I would be removing resistors R13313, R13312 and R13312 and inputting my 75R terminated RGB via 1000 ohm resistors (or 910 ohm) into the ungrounded holes/pads left after removal. (If they are through hole you can use the twist method as shown on 8 bit guy mod)
___________________________________________________
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
Vermifuge
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Re: TV RGB mod thread

Post by Vermifuge »

MarkOZLAD wrote: I would be looking to use an OSD mux method. I would be removing resistors R13313, R13312 and R13312 and inputting my 75R terminated RGB via 1000 ohm resistors (or 910 ohm) into the ungrounded holes/pads left after removal. (If they are through hole you can use the twist method as shown on 8 bit guy mod)
I appreciate the input. This is what i was suspecting. So you suggest remove and not lift one side? replace with 910 ohm on the ungrounded side. what does on the other side?
accskyman
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Re: TV RGB mod thread

Post by accskyman »

Okay, found a very interesting Tv near me since I'm in Central Pennsylvania. Not sure if it's correct but according to the manual it can do 50/60hz PAL and NTSC.

The schematic looks very intimidating, I certainly wouldn't be able to do anything without help, that is if it doesn't already have a scart connector.

It's a Sony KV-AR292m61
https://www.manualslib.com/manual/11423 ... 111#manual

Would it be viable to add a scart connector? Could it be locked out if there's not already one on it?
MarkOZLAD
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Re: TV RGB mod thread

Post by MarkOZLAD »

Vermifuge wrote:
I appreciate the input. This is what i was suspecting. So you suggest remove and not lift one side? replace with 910 ohm on the ungrounded side. what does on the other side?
If they are through hole you can lift the grounded leg and twist your 75 ohm resistor onto it and ground the other leg of the 75 ohm. Inject your RGB into the twisted legs.
___________________________________________________
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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Pikkon
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Re: TV RGB mod thread

Post by Pikkon »

accskyman wrote:Okay, found a very interesting Tv near me since I'm in Central Pennsylvania. Not sure if it's correct but according to the manual it can do 50/60hz PAL and NTSC.

The schematic looks very intimidating, I certainly wouldn't be able to do anything without help, that is if it doesn't already have a scart connector.

It's a Sony KV-AR292m61
https://www.manualslib.com/manual/11423 ... 111#manual

Would it be viable to add a scart connector? Could it be locked out if there's not already one on it?

Very interesting tv you found,you have any pictures of it.

Looks like the rgb and component share the same lines like on jpn sony crt's.
accskyman
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Re: TV RGB mod thread

Post by accskyman »

Pikkon wrote:
accskyman wrote:Okay, found a very interesting Tv near me since I'm in Central Pennsylvania. Not sure if it's correct but according to the manual it can do 50/60hz PAL and NTSC.

The schematic looks very intimidating, I certainly wouldn't be able to do anything without help, that is if it doesn't already have a scart connector.

It's a Sony KV-AR292m61
https://www.manualslib.com/manual/11423 ... 111#manual

Would it be viable to add a scart connector? Could it be locked out if there's not already one on it?

Very interesting tv you found,you have any pictures of it.

Looks like the rgb and component share the same lines like on jpn sony crt's.
So I requested what inputs it has, before I decide to pick it up- the pictures they have aren't very helpful.
Spoiler
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MarkOZLAD
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Re: TV RGB mod thread

Post by MarkOZLAD »

accskyman wrote:
Pikkon wrote:
accskyman wrote:Okay, found a very interesting Tv near me since I'm in Central Pennsylvania. Not sure if it's correct but according to the manual it can do 50/60hz PAL and NTSC.

The schematic looks very intimidating, I certainly wouldn't be able to do anything without help, that is if it doesn't already have a scart connector.

It's a Sony KV-AR292m61
https://www.manualslib.com/manual/11423 ... 111#manual

Would it be viable to add a scart connector? Could it be locked out if there's not already one on it?

Very interesting tv you found,you have any pictures of it.

Looks like the rgb and component share the same lines like on jpn sony crt's.
So I requested what inputs it has, before I decide to pick it up- the pictures they have aren't very helpful.
Spoiler
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Component, 2 x S vid. Can’t be modded for RGB.
___________________________________________________
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
MiteWiseacre
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Re: TV RGB mod thread

Post by MiteWiseacre »

I posted my scenario up above, seems to have been buried a little. Been trying different things and looking for help. One suggestion was that the osd may be digital eight colour, is there a way to identify this definitively from the data sheet?
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Syntax
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Re: TV RGB mod thread

Post by Syntax »

Maybe try mixing h and v sync properly.

Thru a pot....that's very hackish.

Digital will show 5vpp on data sheets generally
MiteWiseacre
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Re: TV RGB mod thread

Post by MiteWiseacre »

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For proper osd mixing you mean combine and add resistors?
Having trouble with my images but the data sheets show there is switching on the OSD RGB for analog or digital, high and low signal to switch.. should I pursue this? Looks like 1v signals are considered digital and .7v signal is analog
jeffez
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Re: TV RGB mod thread

Post by jeffez »

I'm impressed with how simple some of these RGB mods are, that are being done. Especially with the OSD MUX method requiring no toggle switches. I have spent many hours over some weeks trying to get s-video running properly on an old trinny. Seems like s-video is allot harder to get right but that may just be because it isn't all that popular and well documented. I might try doing an RGB mod in future if i can find a decent modable set.
MiteWiseacre
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Re: TV RGB mod thread

Post by MiteWiseacre »

Well I’m stuck with this Diamond Vision.
I do have a line on a Toshiba 27a43c, I know they have pretty good picture but is if a good fit for setting up for vertical arcade games? Don’t see a known rgb mod on this one either.
MarkOZLAD
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Re: TV RGB mod thread

Post by MarkOZLAD »

MiteWiseacre wrote:Well I’m stuck with this Diamond Vision.
I do have a line on a Toshiba 27a43c, I know they have pretty good picture but is if a good fit for setting up for vertical arcade games? Don’t see a known rgb mod on this one either.
Start by getting a service manual. It’s a standard OSD RGB Mux candidate.
___________________________________________________
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
MiteWiseacre
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Re: TV RGB mod thread

Post by MiteWiseacre »

Got my new Toshiba 27a43, pulled it apart and got the service manual. Found some nice jumpers where I can insert into the rgb from between micom and jungle, looks like I need 750R according to the mux diagrams. Thanks for those. The traces are really hard to follow, I’ll have to send blanking right to the leg of jungle.
Found this source for a service manual
https://elektrotanya.com/toshiba_27a43c ... ad.html#dl

Pin 22 R
Pin 21 G
Pin 20 B
Pin 19 blanking

Any thoughts? Going to try this

Edit: so I did it and the results make me very happy!
I didn’t have the resistors to build the proper MUX circuit. So basically used the one I tried on the other TV, 75ohm to ground to a 75ohm res and a 1uF cap in-line on the RGB, using a vga cable from a PC running crt-emudriver, tied both h and v sync together to the composite input and used a pot to dial it in (I know it’s hacky), grabbed 5v from the RF.
It works! I’m shifted to the right but other than that a nicer picture than my WEGA using vga to component. Tomorrow I will clean up my wiring and try proper resistors and mux, then I can make a proper post.
1- I didn’t bother disconnecting the osd, it doesn’t seem to affect the picture and want to try the mux circuit, would it improve picture?
2- I tried using Luma on the s-video input for sync, didn’t work, did I get it wrong(pin 3)? Does it sometimes not work?
MiteWiseacre
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Re: TV RGB mod thread

Post by MiteWiseacre »

So here’s how I modded my Toshiba 27a43
Micon: OEC7074A
Jungle: TB1253AN
Found service manual here:
https://elektrotanya.com/toshiba_27a43c ... ad.html#dl

When you’re pulling the main board out of this set it can kinda seem fused in there, I ended up using a long Philips driver to undo the back of the buttons just to free everything up, there’s really only a clip in the centre and once you get it apart it pops in and out nicely. Was baffled for a bit.

I pulled a female vga socket out of a dead monitor and wired to the pins 1-R, 2-G, 3-B, 10-Ground (soldered a lead right across #6-10 maybe unnecessarily), 13-H, 14-V sync.
I used the components I had around instead of following the RGB Mux guide properly. (The rgb goes through a voltage divider with two 4700ohm resistors after the micom, how does this work with the resistor chart?)
VGA Red -> 75R (terminated to ground ) -> 75R -> 1uF cap -> W127 (same circuit for R,G&B)
W127 is a jumper between pin 34 on the Micom (after the resistors) and pin 20 on the jungle (OSD red input)
W125 is green
W124 is blue
Pulled 5v from the RF input tuner. BPL goes to a cap C002, soldered onto the tuner-side leg, ran to the blanking pin#19 on the jungle, the nearby R615 was a nice spot to tap in.
I combined my H&V sync -> 75R terminated to ground -> composite #1 Y input. (Tried Luma on svideo with no luck)
Put it all on a switch. The osd is sort of useable, just very faint unless I hit the switch and turn off blanking, would probably be easier to read if I had followed the mux instructions properly.
Works very well, offset to the right is all and reading into this issue more.
Thanks for your help guys
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