TV RGB mod thread

Oneinchbiceps · Joined: 11 Jun 2020 Posts: 1

abispac wrote:

So my niece gave me a 19 ich tv its a curtis matches tronics model cm19022s, i could not locate a service manual, it has two chips, a toshiba ta1282n and a zilog 5007 or szm-370th1, i couldnt find information on the zilog chip , but the toshiba i got the pdf datasheet and a gif image

https://datasheetspdf.com/pdf-file/4929 ... /TA1268N/1

Now according to the datasheet and the image, 14 its my blank signal, 15,16,17 are rgb, so it should be a straight mode right?

So I just realise i have the same chassis as the 8bit guy, the same, it might be a little bit more modern but its the same ---smurfing--- one, so all i got to do to succeed its just straight copy his mod ,but i did the mod, exactly as the 8bit guy did, i also had no smoke coming up after getting everything together again, ill just need to test it with groovymame,So i can say im almost done with this mode, i just cant figureout what im missing. I did everything exactly as the 8bit guy did, well, not the fancy conector, as i might add it later on. Hook my pc with my vga brekout cable, and bam, clear colors but bad sync

So i started emudrivers on my other tv (i had both monitors hooked, i always do that on crtdrivers) and dont matter what settings i choose, 15khz, 31khz o 60 khz, i cant get this thing to sync. i can still see that colors are gonna be good, i ust need a bit of help in here please. So so far, as the 8bit guy did, the rgb cables have the 75ohm resistors terminated to ground, all grounds go to ground, i get the 5v volts from the same place, and the sync i try to get it from the yellow rca entrance on the back of the tv. but no luck. Do i need to add a 75ohn resistor on the sync cable as well? or do i need to build the vga cable has he did on his second video? thanks for any help.
This is how far i got.

and a link to the second video where he builds the vga cable.

https://www.youtube.com/watch?v=NkpSBK3g-gA&feature=share

I also have this model and I was thinking about modding it. Funny thing is I took the TV back off tonight to see what kind of chips I had. Anyhow I've notice the AV connector on my television making poor connection so I made sure to re flow the solder on the AV portion before putting the back back on the TV. To be honest though I don't think I had cold solder points upon inspection I got a funny feeling it's yellow jack itself that probably bad. Try wiggling that yellow cable to see if that fixes your sync issue. We should keep in touch seeing how were attempting to mod the same set.

deepthaw · Joined: 11 Jun 2020 Posts: 2

Long time lurker, going to finally try and mod my KV27S42 this weekend.

Instead of soldering components to the wires, I’ve put them on strip board. That way, odds are any mistakes will be limited to an easily removable circuit board. I’m going to run jumper wires to the tv’s pcb.

Does it look like this will work for the connections to osd, jungle, and external RGB via BNC? I’m still getting my feet wet with electronics. I’ve checked continuity and didn’t find any shorts or errant connections.

https://imgur.com/a/ydtp3Fh

Red lines are where I cut the strips on the other side.

tomato16 · Joined: 13 Jun 2020 Posts: 1

Hi there, also a long time lurker of this forum. There is vast amount of information here, I appreciate you all for sharing your knowledge and work.

I am planning to RGB mod my Sony KV-20S10. I was hoping someone could review my steps in case I'm missing anything.

Details

Jungle IC contains unused analog R,G,B IN pins, (16, 17, 18)

Jungle is likely CXA1465AS or CXA1464AS, will confirm when set is opened

will be using D-SUB 15 female connector, connecting to MiSTer only

KV-20S10 service manual

CXA1464AS datasheet

Steps

wire CSYNC IN -> Jungle pin 5 (C)

wire R IN -> 25 ohm resistor, ground, 1uf capacitor -> Jungle pin 16 (R)

wire G IN -> 25 ohm resistor, ground, 1uf capacitor -> Jungle pin 17 (G)

wire B IN -> 25 ohm resistor, ground, 1uf capacitor -> Jungle pin 18 (B)

wire SET5V -> rocker switch -> 100 ohm resistor -> Jungle pin 15 (YS)

Disable VM via service menu

If RGB analog pins turn out to be disabled, set everything on the ID side of the service menu to 1, reset the service menu with 8 + enter (thank you fandangos)
Questions

Is it okay to solder to the legs of Jungle IC without lifting them?

Is it safe to connect CSYNC IN to the Jungle without any resistance?

How could I tell if my analog RGB pins have been disabled?
I collected my info from mods done by pcbjunkie, suprcrackers, GoXoD and fandangos. Thank you all for posting your work on this forum, it has been very helpful.

Osirus · Joined: 16 Jun 2020 Posts: 4

Hello all, I've been wanting to try this for a while. I went out and picked up a Toshiba CF27E50 from a thrift store. It says the chassis is TAC 9515. Anyone modded this set? I haven't been able to find a service manual for it specifically, I did find one for a CF27D50, but I don't know what the difference is.

https://www.manualslib.com/manual/12458 ... e=3#manual

jeffez · Joined: 20 Nov 2019 Posts: 46 Location: Australia

MarkOZLAD wrote:

cpyne wrote:

flynnsbit wrote:

Pin 38 Luma In is where sync is going in.

If you follow the diagram you'll see that the jungle is taking IF in, creating composite video that goes out the VIDEO OUT and then gets fed into the Luma and Chroma in pins.

Could I just tap csync right into pin 38? Or would some additional changes be needed since this is a luma input?

I would say you would want to 75 ohm terminate it and inject via a cap. Possibly want to disconnect the chroma line.

Just curious what rating cap you would recommend? I found a lower 10-100nF one had negative effects but a much larger 10-100MF seemed ok but probably overkill. So far i have just injected it straight from the luma pin (svideo mod..) as that always worked fine. Is it still best to have the 75R and coupling capacitor even if it's just for sync?

MarkOZLAD · Joined: 18 May 2017 Posts: 702

jeffez wrote:

Just curious what rating cap you would recommend? I found a lower 10-100nF one had negative effects but a much larger 10-100MF seemed ok but probably overkill. So far i have just injected it straight from the luma pin (svideo mod..) as that always worked fine. Is it still best to have the 75R and coupling capacitor even if it's just for sync?

I haven't done this exact mod myself so I don't know for sure but the patterns I tend to notice are 75 ohm termination and 100nF (0.1uF) capacitors. I have seen 1uF and 4.7uF used as well on the Y/External CVBS lines.

I would be consulting datasheets and alternate schematics to see what I could find out for the chip I was modding though.

jeffez · Joined: 20 Nov 2019 Posts: 46 Location: Australia

MarkOZLAD wrote:

jeffez wrote:

Just curious what rating cap you would recommend? I found a lower 10-100nF one had negative effects but a much larger 10-100MF seemed ok but probably overkill. So far i have just injected it straight from the luma pin (svideo mod..) as that always worked fine. Is it still best to have the 75R and coupling capacitor even if it's just for sync?

I haven't done this exact mod myself so I don't know for sure but the patterns I tend to notice are 75 ohm termination and 100nF (0.1uF) capacitors. I have seen 1uF and 4.7uF used as well on the Y/External CVBS lines.

I would be consulting datasheets and alternate schematics to see what I could find out for the chip I was modding though.

Cool ok yeah it looks like a 100nF is maybe not letting some frequencies through necessary for sync. The top of the screen gets distorted. I'll look back at the datasheet and see if there's any caps further down the line on the tv. Fair chance i'll see a higher rating one like you say 1-4.7uF
EDIT : Found a 0.47uf

tacoguy64 · Joined: 30 Dec 2014 Posts: 508

Im stuck. I can't get any of the menu overlays to show up. I'm getting something but its dark and can barely see...

https://www.youtube.com/watch?v=taPfJ79iCVE

Im pretty much following maxtherabits steps with the exception of using a scart connector. I had to make connections to sync, grounds, audio, and blanking all to the scart pin connector to their points on the board. The only other deviation was using W697 Ys to JUNGLE connecting to both pin 16 on my scart connector and using it to connect to the switch. Which does seem switch between the two modes. Maybe i was suppose to connect W785 Ys from MICON to the scart blanking pin 16? Am I looking at the right direction or am I way off?

Thanks!

Osirus · Joined: 16 Jun 2020 Posts: 4

My Toshiba has S-Video which is actually pretty good, not wanting to mess with that (yet) I've moved on. Instead I think I will try modding my Panasonic CT-32G4A since it only has Composite Input which is crappy. Looks like someone has done a similar one here: http://shmups.system11.org/viewtopic.ph ... &start=449

I can't find a schematic for the TV, but I took a look at the chassis. There are the standard 2 ICs that I can see. An AN5166K which is a Jungle IC and a MN1874085 which looks like the OSD chip.

I want to use a VGA connector to connect this to a card using CRT Emudriver/GroovyMAME for 15 kHz arcade games. Instead of using pin 16 on the SCART plug like in the v2 Mux Circuit I thought I could use pin 9 on VGA since it's 5V for blanking. Would this work?

tacoguy64 · Joined: 30 Dec 2014 Posts: 508

Troubleshooted for a little bit today. Removed the connection from W697 Ys to JUNGLE to pin 16 on the scart connector just to see what would happen and still the same. I can toggle between the different inputs on the TV but thats about it. Volume seems gone and everything still seems like it's too dark. I wonder if maybe I just messed up on the RGB lines on the SCART. Everything looks like on the mux. On the SCART connector I have 75R connected on each rgb pin. Got my ground point for all the pins on the SCART coming from W745 analog ground. And a 390R resistor also on each of the RGB lines. I'm now thinking rgb lines might be messed up. Screen still shows some color but its the most faintest amount and it's all dark. On the plus side, it looks like i got sync right. I know the OSD still works, but it's too dark to see anything.

flynnsbit · Joined: 12 Apr 2020 Posts: 48

Lookes like you don't have blue, and maybe sync is reversed or negative or something. Did you go into a YS pin or something else? Does a normal composite signal look fine on the TV (and what about the menu on composite) if you have blanking turned off.

tacoguy64 · Joined: 30 Dec 2014 Posts: 508

flynnsbit wrote:

Lookes like you don't have blue, and maybe sync is reversed or negative or something. Did you go into a YS pin or something else? Does a normal composite signal look fine on the TV (and what about the menu on composite) if you have blanking turned off.

I checked underneath the board and turns out the spot where I removed the 4 resistors connected to the jungle chip, i installed a diode on the Ys blanking line when i was only supposed to install it on the RGB line (check steps 6,7,8 on maxtherabbits post) Removing the diode now gets me some color and I can now see the menu again. I checked all the RGB lines and aside from maybe using a bunch of solder, everything looked fine. Unfortunately, my picture is all blue and sync is off.

Should also note these diodes were giving me some problems installing them. So im not sure if that can have something to do with my issues.

composite input fast blanking off
https://www.youtube.com/watch?v=76T3VxiL_e4

fast blanking on rgb
https://www.youtube.com/watch?v=-1O3LEInO_Y

Also i had tied component video Y as my sync. But moved it all to input 1 composite. Here's how i got it hooked up to the scart pin

Spoiler: show

tacoguy64 · Joined: 30 Dec 2014 Posts: 508

Haven't been able to make much progress.
Looking at the MarkOZLAD mux diagram, does pin 16 need to be set up the same way as the rgb pins do? that is to say it needs a 75 ohm to ground and another resistor with a wire attached going jungle chip or the micon? Cant pin 16 connect straight to micon or jungle?

I tried a straight connection to both W697 Ys to jungle and W785 Ys from micon to pin 16 with no luck. Sorry to flood this thread but i'm running out of ideas here.

deepthaw · Joined: 11 Jun 2020 Posts: 2

Can an RGB mod be done that bypasses the jungle chip entirely by tapping into its RGB out lines?

I have a TV which I suspect has a bad jungle chip and I thought that might be a good way to test. It wouldn't be permanent.

MarkOZLAD · Joined: 18 May 2017 Posts: 702

tacoguy64 wrote:

Haven't been able to make much progress.
Looking at the MarkOZLAD mux diagram, does pin 16 need to be set up the same way as the rgb pins do? that is to say it needs a 75 ohm to ground and another resistor with a wire attached going jungle chip or the micon? Cant pin 16 connect straight to micon or jungle?

I tried a straight connection to both W697 Ys to jungle and W785 Ys from micon to pin 16 with no luck. Sorry to flood this thread but i'm running out of ideas here.

If you're having trouble with blanking, use a switch or hardwire it until you sort out other issues.

The OSD mux diagram shows how to set up for pin 16 if your jungle blanks at around 1.5V. Essentially you end up mixing the blanking in a very similar manner to the RGB lines.

cyborc · Joined: 25 Mar 2009 Posts: 249 Location: USA

Has anyone ever designed a PCB to make modding a little easier? I'm thinking something that has pads for R G B and Sync in, pads/holes for the termination and inline resistors, pads for RGB and Sync out, and a spot for 2 resistors to divide 5v into whatever voltage is needed for the blanking pin. Also, maybe a spot for a resistor to lower Sync voltage for people who use extron devices or other devices that output TTL level sync. Preferably it would use SMD resistors for a smaller PCB.

I usually use a stripboard for all the RGB mod components, but this would make the job a bit faster and cleaner.

I have zero experience designing pcbs, but perhaps I should start learning... something this simple shouldn't be too difficult to design, right?

skum · Joined: 08 May 2018 Posts: 83 Location: Denmark

cyborc wrote:

Has anyone ever designed a PCB to make modding a little easier? I'm thinking something that has pads for R G B and Sync in, pads/holes for the termination and inline resistors, pads for RGB and Sync out, and a spot for 2 resistors to divide 5v into whatever voltage is needed for the blanking pin. Also, maybe a spot for a resistor to lower Sync voltage for people who use extron devices or other devices that output TTL level sync. Preferably it would use SMD resistors for a smaller PCB.

I usually use a stripboard for all the RGB mod components, but this would make the job a bit faster and cleaner.

I have zero experience designing pcbs, but perhaps I should start learning... something this simple shouldn't be too difficult to design, right?

I did this some time ago: https://oshpark.com/shared_projects/JpxJNG1c

Doesn't do everything you mention, but lots of it. It's designed for SCART with audio passthrough, but technically you can just use the pads for further wiring.

Osirus · Joined: 16 Jun 2020 Posts: 4

Looking at the Datasheet for my jungle I think I have identified the pins I need to use:

https://pdf1.alldatasheet.com/datasheet ... 5165K.html

I won't actually solder sync directly on the chip like that, that was just to identify the pin. I'll probably put it on the composite-in connector.

Now, the blanking and RGB input pins:

Anything standing out here as out of the ordinary?

As for the OSD chip, unfortunately from the datasheet I can't tell which pins are the OSD out:

https://pdf1.alldatasheet.com/datasheet ... 74085.html

cyborc · Joined: 25 Mar 2009 Posts: 249 Location: USA

skum wrote:

cyborc wrote:

Has anyone ever designed a PCB to make modding a little easier? I'm thinking something that has pads for R G B and Sync in, pads/holes for the termination and inline resistors, pads for RGB and Sync out, and a spot for 2 resistors to divide 5v into whatever voltage is needed for the blanking pin. Also, maybe a spot for a resistor to lower Sync voltage for people who use extron devices or other devices that output TTL level sync. Preferably it would use SMD resistors for a smaller PCB.

I usually use a stripboard for all the RGB mod components, but this would make the job a bit faster and cleaner.

I have zero experience designing pcbs, but perhaps I should start learning... something this simple shouldn't be too difficult to design, right?

I did this some time ago: https://oshpark.com/shared_projects/JpxJNG1c

Doesn't do everything you mention, but lots of it. It's designed for SCART with audio passthrough, but technically you can just use the pads for further wiring.

Awesome, thanks! I normally use HD15 or BNC but I can certainly adapt this to those connectors.

MarkOZLAD · Joined: 18 May 2017 Posts: 702

tomato16 wrote:

Hi there, also a long time lurker of this forum. There is vast amount of information here, I appreciate you all for sharing your knowledge and work.

I am planning to RGB mod my Sony KV-20S10. I was hoping someone could review my steps in case I'm missing anything.

Details

Jungle IC contains unused analog R,G,B IN pins, (16, 17, 18)

Jungle is likely CXA1465AS or CXA1464AS, will confirm when set is opened

will be using D-SUB 15 female connector, connecting to MiSTer only

KV-20S10 service manual

CXA1464AS datasheet

Steps

wire CSYNC IN -> Jungle pin 5 (C)

wire R IN -> 25 ohm resistor, ground, 1uf capacitor -> Jungle pin 16 (R)

wire G IN -> 25 ohm resistor, ground, 1uf capacitor -> Jungle pin 17 (G)

wire B IN -> 25 ohm resistor, ground, 1uf capacitor -> Jungle pin 18 (B)

wire SET5V -> rocker switch -> 100 ohm resistor -> Jungle pin 15 (YS)

Disable VM via service menu

If RGB analog pins turn out to be disabled, set everything on the ID side of the service menu to 1, reset the service menu with 8 + enter (thank you fandangos)
Questions

Is it okay to solder to the legs of Jungle IC without lifting them?

Is it safe to connect CSYNC IN to the Jungle without any resistance?

How could I tell if my analog RGB pins have been disabled?
I collected my info from mods done by pcbjunkie, suprcrackers, GoXoD and fandangos. Thank you all for posting your work on this forum, it has been very helpful.

wire G IN -> 25 ohm resistor, ground, 1uf capacitor -> Jungle pin 17 (G)
Not sure why you've chosen 25 Ohm resistor. Should be 75 Ohm. For the capacitor the datasheet of the CXA1465AS there are multiple values shown in the wiring diagrams. 0.22uF on the test circuit and 10uF on page 36... I'd go with 0.1uF.

Is it safe to connect CSYNC IN to the Jungle without any resistance?
I'd normally say put the sync into the AV port - even if this means soldering to the points underneath it, but it seems this is RF only right? Hmmmm....

Jungle pin 3 is the video/sync input as far as I can tell. I'd be looking to lift the leg of C304 farthest from the jungle and inject my sync into it. As you want to use VGA csync I would be sending the csync into a 1000 Ohm resistor and then adding a 75 Ohm to ground and then into the leg of C304. This will attenuate the CSYNC to a level the TV expects.

wire SET5V -> rocker switch -> 100 ohm resistor -> Jungle pin 15 (YS)
I'd send 5V to a switch and then through a 470 Ohm resistor into the leg of L001 thats closest to IC101.

Is it okay to solder to the legs of Jungle IC without lifting them?
I've never lifted a chip leg to mod a set. Take some detailed photos of the top and bottom of the chassis circuits. You might find a better way. However....If the legs are just left floating, not grounded you should be ok to solder to them. The schematic suggests they are all linked to a 10K and then ground (R325), this may need to be removed to leave them floating.

EDIT: Looking a bit closer at the schematic, you may need to lift the RGB legs. Possibly better to just snip them near the circuit board.

Osirus · Joined: 16 Jun 2020 Posts: 4

I assume AC (Pulse) for the RGB inputs means PWM which is actually digital and won't work?

MarkOZLAD · Joined: 18 May 2017 Posts: 702

Osirus wrote:

I assume AC (Pulse) for the RGB inputs means PWM which is actually digital and won't work?

The Datasheet is a little confusing, I can't tell you whether it will work or not. Could just give it a shot.

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