TV RGB mod thread

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yonnyderamos
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Joined: Tue Jun 06, 2023 1:16 am

Re: TV RGB mod thread

Post by yonnyderamos »

Syntax wrote:Finished up today on a cool old Philips set I found at the tip.
It was rusty and full of mud and worms but the speakers sound great and the picture was nice.
Had to OSD hack this one as there was no external RGB input.
Jungle was a Philips TDA8361 http://www.alldatasheet.com/datasheet-p ... A8361.html

The blanking required sweeping a 10k pot with ground and 5v, wouldn't work with just 5v across a 10k pot.
End result was 2x2.4k resistors as a voltage divider to the blanking. would of been sitting around 3v I never checked.

3 tv's finished in a day I think I should sleep..

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hello syntax I have to ask you a question since I have the same Philips television that you show. Could you help me with the scheme of the modification of this television? the model is philips 20gx1550/77b
titan91
Posts: 58
Joined: Sun May 14, 2023 1:44 pm

Re: TV RGB mod thread

Post by titan91 »

Final update on my Philips/Magnavox MT2501 TV. I removed the previous series 0.1uf ceramic capacitor for the CVBS2 input and replaced it with a proper 2.2uf one. Unfortunately the TV is still shutting down when a PSOne or PS2 is connected via composite. Today I tried the PS2. Now before I was using a cheap third party s-video cable and came to find out the Y/C pins on this cable are either shorted together or there is RF crosstalk in the cable itself. When connecting Y to the composite input on my LCD TV I get color, and that shouldn't be happening. My Sony PVM doesn't seem to care, and the picture looks fine with s-video.

So I was thinking maybe there is an issue with the wiring of the composite connection on that cable as well. I do have a genuine Sony PS2 component cable. So I hooked the PS2's green Y connector up to CVBS2 and STILL the TV shuts down immediately when I turn on the console. So something about sync from specific Sony products this TV was not calibrated for on its factory missing and deactivated CVBS inputs.

I see the writing on the wall with this overly cheap and locked down set so I'm just going to factory restore it by removing my taps, terminations, and re-terminating CVBS1 with 300Ω to ground as it was originally. I'll also need to reset OB5 to 0. Hopefully this will get rid of the jailbar pattern on the RF channels and restore the tuner. If not, I will donate the set to a local arcade expo for a tube swap in an arcade cabinet.
joebliksem
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Joined: Thu Jan 26, 2023 6:45 am

RGB mod for an Aiwa VX-t1420 - NO BLANKING

Post by joebliksem »

Hi! I am modding an Aiwa VX-T1420 (tv/vcr combo) and I am struggling to get it to blank or display any RGB signal at all. I saw someone modded a set like this a couple of years ago on this forum and I am following his mod but not getting any results. This is the work I have done so far. Am I doing anything obviously stupid?

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titan91
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Re: RGB mod for an Aiwa VX-t1420 - NO BLANKING

Post by titan91 »

joebliksem wrote:Hi! I am modding an Aiwa VX-T1420 (tv/vcr combo) and I am struggling to get it to blank or display any RGB signal at all. I saw someone modded a set like this a couple of years ago on this forum and I am following his mod but not getting any results. This is the work I have done so far. Am I doing anything obviously stupid?

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Are you in composite input mode and feeding a sync signal to the composite input port?
joebliksem
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Re: TV RGB mod thread

Post by joebliksem »

That's a good question - I am unable to switch to composite mode. The remote has a tv/monitor button but it doesn't seem to do anything. I plugged in a Wii to test and I get no composite signal out. VHS output works. I tried a universal remote just to be sure but nothing. it doesn't switch to composite out. I'm currently combing over the schematics but I'm stumped. The unit has a separate daughter board that handles composite and I can tell that there RGB lines on the main board that would have connected to the daughter-board if it was a scart version.

I wonder if there is a way to force composite on the board? I'm only interested in using it an RGB monitor, so I don't mind overriding other features.

Here's the schematics for the set https://drive.google.com/file/d/1gEJat9 ... sp=sharing
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ledoeye
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Re: TV RGB mod thread

Post by ledoeye »

Hi! I RGB modded a JVC D series 20' like a week ago and while the mod was successful there is still something bugging me
that I would like to understand why it's doing this.
I used this guide also some pics :

https://imgur.com/a/aFJ9WjF

https://sector.sunthar.com/guides/crt-r ... gb-mux-mod

Although it's a different TV model it still uses the same board as my D series.

So i mod the TV and the first issue was that the TV was stuck in RGB mod and the SPDT switch wouldn't work, as if it the switch wasn't there at all.
While troubleshooting for a good while, the fix that i found was removing the 1k resistor off the blanking line as well as the diode and that did the trick, no longer stuck in RGB mod and SPDT switch works perfectly.
I tried having just the diode in line but i get back to square one and switch doesn't work so I just kept it without it.

While assembling the TV back, i thought i had plugged everything so I turn on the TV and hear a nasty sound and realized that i forgot to insert the anode cap back in ( I know, I'm stupid ) so i turn OFF the TV as soon as I could.
I insert the anode cap back and turn ON the TV and all i get is a standby red light and black screen no degaussing sound or anything.
I disassemble everything again and with the help of a reddit user, I found out that the Fuse of the main board blew which is rated 125V 1.25A.
New Fuse with the same rating , or so I thought, comes in and this Fuse that I ordered of Ebay was actually 250V 1.25A instead of 125V. I spoke with someone on Discord about it and they told me it was fine.
I grab the new Fuse and install it on the TV and it works perfectly again, what a relief!
The next day i assemble the TV back, and start playing some games for a couple of hours and TV works perfectly no issues.

The very next day i turn on the TV and it doesn't turn on at all no life no degaussing sound nothing, i was mind blown like what could've possibly happened between today and yesterday!?!?
What i found out was that the TV doesn't turn ON when the RGB spdt switch is ON, TV set only turns ON when switch is turned OFF and then i can turn the spdt switch back to RGB and play normally.

This is the issue I'm having now, not sure what’s wrong, could it be the new installed fuse? Or is it the fact that I removed the 1k resistor and diode?
tongshadow
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Re: TV RGB mod thread

Post by tongshadow »

The installation on that switch doesnt look right, you're supposed to use all the 3 poles.
Middle pin - Common path to the Jungle IC
Upper pin - RGB Blanking voltage (I'll assume you're using 5v)
Lower pin - Blanking voltage from the Microprocessor (OSD blanking/RGB OFF)

The reason the TV wont turn on with RGB is because your 5v blanking voltage is also going into the Microprocessor, so the TV thinks there's a problem and wont turn on.
I couldn't find the diode you mentioned on that schematic, but this is how I would do it based on this schematic: https://sector.sunthar.com/assets/jvc-a ... 0e6014.jpg
-Remove R735 to isolate the original blanking line
-Connect a wire from R734 to the lower pin of the switch
-Connect a wire from L705 to the middle pin
-Connect the external 5v blanking to the upper switch
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ledoeye
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Re: TV RGB mod thread

Post by ledoeye »

tongshadow wrote:The installation on that switch doesnt look right, you're supposed to use all the 3 poles.
Middle pin - Common path to the Jungle IC
Upper pin - RGB Blanking voltage (I'll assume you're using 5v)
Lower pin - Blanking voltage from the Microprocessor (OSD blanking/RGB OFF)

The reason the TV wont turn on with RGB is because your 5v blanking voltage is also going into the Microprocessor, so the TV thinks there's a problem and wont turn on.

Thank you for the reply. The reason i wired the switch this way was because my other JVC that I RGB modded was wired the same way and doesn't have this issue but i guess each TV is different.
When you say Middle Pin Common Path to the Jungle IC, where exactly should I solder a wire?
Sorry for the noob question, i'm still fairly new to RGB modding, this is like my 3rd mod.

EDIT : Nvm you already answered my question lol Thank you tongshadow, i will work on it again today and let ya know.

Here's the schematic so you can see which resistor / diode i removed https://imgur.com/a/gZrcgOj
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ledoeye
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Re: TV RGB mod thread

Post by ledoeye »

tongshadow wrote:The installation on that switch doesnt look right, you're supposed to use all the 3 poles.
Middle pin - Common path to the Jungle IC
Upper pin - RGB Blanking voltage (I'll assume you're using 5v)
Lower pin - Blanking voltage from the Microprocessor (OSD blanking/RGB OFF)

The reason the TV wont turn on with RGB is because your 5v blanking voltage is also going into the Microprocessor, so the TV thinks there's a problem and wont turn on.
I couldn't find the diode you mentioned on that schematic, but this is how I would do it based on this schematic: https://sector.sunthar.com/assets/jvc-a ... 0e6014.jpg
-Remove R735 to isolate the original blanking line
-Connect a wire from R734 to the lower pin of the switch
-Connect a wire from L705 to the middle pin
-Connect the external 5v blanking to the upper switch

Just got done wiring the spdt switch tongshadow, sadly i'm back to square one stuck in RGB mode, switch doesn't do anything if i flip it down / up. The TV does turn ON now even with the switch flipped to ON position.

Here's couple pics of the new wiring https://imgur.com/a/HQWHb8M
tongshadow
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Re: TV RGB mod thread

Post by tongshadow »

Unlikely, but I wonder if it could be a bad switch. Use a multimeter and check the continuity between the middle pin and upper/lower ones. It should beep between mid/upper if the switch is down, and mid/lower if it's up. It shouldnt beep between all 3 pins at the same time.
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ledoeye
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Re: TV RGB mod thread

Post by ledoeye »

tongshadow wrote:Unlikely, but I wonder if it could be a bad switch. Use a multimeter and check the continuity between the middle pin and upper/lower ones. It should beep between mid/upper if the switch is down, and mid/lower if it's up. It shouldnt beep between all 3 pins at the same time.
Yeah i already tested it with my multimeter and it's working fine. The switch works if the voltage (5v) wire is soldered to the middle pin but i guess this is not the optimal way of wiring the switch.
Thecasperlife
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Joined: Tue Jun 20, 2023 1:07 pm

Re: TV RGB mod thread

Post by Thecasperlife »

Hey guys!
I just successfully modded my 27V-KV42 following this guide:

https://github.com/brendanseattle/SonyR ... /README.md

However, I did have to disconnect the 1,000 ohm resistor from my blanking line for the switch to function, as the person who wrote the guide did. It looks like another person also had the same issue.

Is this safe to do? Or should I connect another value resistor to the line?

Thanks in advance!
tongshadow
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Re: TV RGB mod thread

Post by tongshadow »

If it's showing composite while off and RGB while on, then you should leave it be and just consider this a quirk of the set.
I have always wired by RGB mux modded TVs that way without issues. I'll also mention my switches have 3 positions, up/mid/down.
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ledoeye
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Re: TV RGB mod thread

Post by ledoeye »

tongshadow wrote:If it's showing composite while off and RGB while on, then you should leave it be and just consider this a quirk of the set.
I have always wired by RGB mux modded TVs that way without issues. I'll also mention my switches have 3 positions, up/mid/down.

My stock inputs ( Composite/Svideo/Component ) only show black screen, so yea atm the set is just RGB which is fine tbh since imma be using RGB more anyway but i would like to have the option.
Could you link your switches?
tongshadow
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Re: TV RGB mod thread

Post by tongshadow »

It's just a simple 3-way switch, I use them because of 8-bit's recommendation:
https://youtu.be/NkpSBK3g-gA?t=24
https://i.imgur.com/sSP3tC9.jpeg
kinokopower
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Joined: Sun Aug 08, 2021 3:53 am

Re: TV RGB mod thread

Post by kinokopower »

Help to RGB mod Sony KV-34-36DRC430. Chassis DA-4. HD SET

This is a HD set with native 540p/1080i screen, I don't know if somebody has done this on any HD CRT before but as far as I know it's possible.
I've been modding SD sets for quite sometime so I'm familiar with the process but I have some doubts, hopefully you guys can help me out

First, I already verified and I'm almost sure that it accepts analog RGB, even though I was unable to find the datasheet to junglechip CXA2170Q, I was able to find the datasheet for the MAINCON M306V7MG-XXXFP
https://html.alldatasheet.com/html-pdf/ ... 6V7MG.html

Second: RGB LINES
Every RGB line has two inline resistors and two resistors to ground. I want to use MarkOZLAD OSD Mux RGB Calculator, usually you have one inline resistor and then the one you need to remove is the one to goes to ground, but here I'm not sure of what to do or how to calculate the resistance required on the external RGB lines in order to correctly terminate the OSD RGB.

Example: INLINE BLUE || R2374 (0ohms, which is weird, no value on service manual) R2376 (47ohms to ground) + R2329 (330 ohms to ground) + R2373 (100ohms)

Third: Blanking, is it safe to just inyect 3v?, seems pretty "standard", but there are no diodes on the blanking line, just a series of resistors and caps. Usually you add the voltage to a point after a diode near the jungle chip

THANKS!


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Last edited by kinokopower on Tue Jul 04, 2023 7:56 pm, edited 1 time in total.
tongshadow
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Re: TV RGB mod thread

Post by tongshadow »

This is pointless as good transcoders like the RGB2COMP exist, so you're the first person trying this.
alamone
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Re: TV RGB mod thread

Post by alamone »

tongshadow wrote:This is pointless as good transcoders like the RGB2COMP exist, so you're the first person trying this.
I don't know if it's "pointless", sure it's easier to use a transcoder since converting to component video has minimal quality degradation, but it's still an unnecessary conversion if you can just feed it straight RGB.
retrogamer47658
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Re: TV RGB mod thread

Post by retrogamer47658 »

Hey guys, back again with a Panasonic Model CT-20G14A. This set is pretty typical in terms of the whole OSD circuit, except for two things. I've included a schematic I made to give a better understanding of what's going on.

First, factory grounding resistors have been replaced with 22pF capacitors. I've currently removed C036, C037, and C038, which had the expected results; the OSD became a little "unstable" but is otherwise unharmed. However, things get more complicated from here. Attempting to add 75 ohm termination resistors to the external RGB lines completely shuts off RGB, both internal and external. I'm assuming this is related to the fact that there were never grounding resistors to begin with, so trying to force termination resistors into the circuit won't work.

Second, blanking from the microcontroller is actually two pins: YM and YS. I haven't measured voltages or anything else on these pins, but it seems like they converge into one line that goes into a "YM & YS" pin on the jungle (labeled as just "YS" in my schematic). I'm not even quite sure what the YM pin is or what function it has, which actually brings me to my next point.

So after wiring up the external RGB as shown and removing C036, C037, C038, and R015, the external RGB will only show up for a second after turning on the console; it starts out bright and quickly fades to nothing. I suspect I may need to add 0.1uF caps on the RGB lines, but considering the quirks of this set it could need something else. It could also be something to do with the blanking, but if RGB shows up in the first place then I don't think that's likely the issue. Also, the OSD RGB completely cuts when I plug in the SCART cable; not too sure what that could indicate though.

Any thoughts on this are appreciated!

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tongshadow
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Re: TV RGB mod thread

Post by tongshadow »

retrogamer47658 wrote:Second, blanking from the microcontroller is actually two pins: YM and YS. I haven't measured voltages or anything else on these pins, but it seems like they converge into one line that goes into a "YM & YS" pin on the jungle (labeled as just "YS" in my schematic). I'm not even quite sure what the YM pin is or what function it has, which actually brings me to my next point.
The Jungle's datasheet will you what's the function of each pin and what blanking voltage it needs. See if you can find it.
retrogamer47658
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Re: TV RGB mod thread

Post by retrogamer47658 »

tongshadow wrote:The Jungle's datasheet will you what's the function of each pin and what blanking voltage it needs. See if you can find it.
Unfortunately, I just checked again, and nothing - I can only find one datasheet that is only two pages and provides no useful info.
KPackratt2k
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Re: TV RGB mod thread

Post by KPackratt2k »

First, you've mixed the Jungle chip with the Microcontroller. The AN5166K is your Jungle chip, the closest datasheet I could find is for an AN5165K.

Second, the RGB inputs of this jungle chip is designed for an RGB signal with a DC offset. You will need to amplify the RGB signal from your console before it enters the jungle chip. Injecting it directly won't work properly.

Here are a few examples of a DC offset circuit for the jungle chips that require it:
https://shmups.system11.org/viewtopic.p ... 7#p1492467
https://shmups.system11.org/viewtopic.p ... 7#p1495137
https://crtdatabase.com/crts/panasonic/ ... -ct-s1390y

Bear in mind that these methods are experimental at the moment, so you may need to do some tinkering to get it to look correct.
retrogamer47658
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Re: TV RGB mod thread

Post by retrogamer47658 »

KPackratt2k wrote:First, you've mixed the Jungle chip with the Microcontroller. The AN5166K is your Jungle chip, the closest datasheet I could find is for an AN5165K.
Oh, duh! I think I just mislabeled them in the schematic, but I'll double check that I actually soldered my RGB lines to the jungle inputs.

I'll experiment with the different methods of amplification you've provided, but I'm still not sure what would cause the OSD to cut out when I plug in my SCART cable (when the console is off). Any thoughts on why that would be occurring? Thanks!
vegeta4ss
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Location: Fort Mill, SC

Re: TV RGB mod thread

Post by vegeta4ss »

I am modding a Phillips PR1917 C125, or planning to..I'm still learning a lot of this stuff.

It has the TDA8373 chip and based on other posts from a couple of years back I know the pins and some of the voltages for a RGB mod.

There's one main difference in my crt, it doesn't have composite on board. It came rf only but the chassis had several build configs so I was wondering if I can wire in a composite jack and use it for sync? The tv will have no other purpose other than gaming in RGB.

Since I'm still very new to this stuff, i'm not quite sure it will work. I've attached some diagrams and cvbs info that may help.

If I can't mod this thing that's cool too I'll just recap it and find another CRT. Thanks to anybody that has time to look and comment.

Block Diagram:
https://drive.google.com/open?id=1-Gs_- ... p=drive_fs

TDA8373 pinout:
https://drive.google.com/open?id=1-FMBu ... p=drive_fs

TDA8373 datasheet:
https://drive.google.com/open?id=1-NLnb ... p=drive_fs

CVBS stuff:
https://drive.google.com/open?id=1-JHnN ... p=drive_fs
https://drive.google.com/open?id=1-M0Ta ... p=drive_fs
tongshadow
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Re: TV RGB mod thread

Post by tongshadow »

The issue with composite modding is finding a way make the TV switch to the AV channels, this is where your synced RGB signal will appear. Find the service manual of your TV and see if it can be enabled through the service menu. If not, then this requires editting the EEPROM.
This is why I avoid RF only sets.
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BazookaBen
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Re: TV RGB mod thread

Post by BazookaBen »

tongshadow wrote: If not, then this requires editting the EEPROM.
I haven't been following this thread. Has anyone been hardcore enough to edit their CRT's EEPROM?
kinokopower
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Re: TV RGB mod thread

Post by kinokopower »

alamone wrote:
tongshadow wrote:This is pointless as good transcoders like the RGB2COMP exist, so you're the first person trying this.
I don't know if it's "pointless", sure it's easier to use a transcoder since converting to component video has minimal quality degradation, but it's still an unnecessary conversion if you can just feed it straight RGB.
Yeah, plus this HD CRT (DRC 430) has an issue. It displays OSD colors perfectly, but there are no colors on any input or in any other way (I already tried a lot of things to fix it) So inyecting RGB seems to be the perfect solution, plus it would skip all that digital image processing.

The issue I Have is with the value for the RGB lines which has 4 resistors
Example: INLINE BLUE || R2374 (0ohms, which is weird, no value on service manual) R2376 (47ohms to ground) + R2329 (330 ohms to ground) + R2373 (100ohms)
I already edited my post because it was not showing the attached pictures
vegeta4ss
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Re: TV RGB mod thread

Post by vegeta4ss »

tongshadow wrote:The issue with composite modding is finding a way make the TV switch to the AV channels, this is where your synced RGB signal will appear. Find the service manual of your TV and see if it can be enabled through the service menu. If not, then this requires editting the EEPROM.
This is why I avoid RF only sets.
Good info, thanks. Will try to get a universal remote to work with it. Looking at a service manual for nearly identical model shows a feature code for Aux_In so maybe there's hope yet.

per avoiding RF sets, yeah I honestly thought the guy said it had composite on the front but it was free.
retrogamer47658
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Re: TV RGB mod thread

Post by retrogamer47658 »

Hey everyone, quick follow-up on that Panasonic I'm trying to mod. I've made a DC offset circuit similar to the one by MarkOZLAD: https://shmups.system11.org/viewtopic.p ... 7#p1492467, which has worked well and given me a stable picture. However, I'm still faced with one final issue. The external RGB is excessively bright, and incredibly washed out as well. It's not fully monochrome, but it's far from what it should look like; I've included a photo to give a better idea of what the picture looks like right now (note that the set's brightness has been turned down by about half in this photo). Re-adding the 75 ohm termination resistors seems to have made the picture even brighter than it was before, which is kinda annoying. Any ideas as to what could be causing this? Image
vegeta4ss
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Re: TV RGB mod thread

Post by vegeta4ss »

I picked up another free crt in my area this weekend, a Sylvania srt2232x

service manual:https://drive.google.com/open?id=1-OFo3 ... p=drive_fs
notes1:https://drive.google.com/open?id=1-RDr0 ... p=drive_fs
notes2:https://drive.google.com/open?id=1-S83d ... p=drive_fs

After reviewing all the schematics looking for OSD and sync lines I came to the conclusion that the Micon and Jungle must be the same IC. Does this mean no chance of modding this one too? This one's at least got stereo, s-video, composite, and audio out (so still a better choice than the Philips I posted about). 50% of my quest to RGB mod a crt is to have a solid backup to my Trinitron for the inevitable day it gives out. At least the Sylvania can be that if its not moddable.
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