8 Bit Guy CRT TV RGB Mod Log

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MarkOZLAD
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Joined: Thu May 18, 2017 12:39 pm

Re: 8 Bit Guy CRT TV RGB Mod Log

Post by MarkOZLAD »

undone.evil wrote:hello i was looking at the wiring diagram from the 8 Bit Guys television and noticed that the resistors on the RGB lines appear to be 3.9K and on your diagram you have 5.4K. im modding my tv for RGB and was just wondering if this is a mistake or if im missing something. thank you
Without going back through my notes I would suggest that the schematic showed different values than were actually installed in the TV. There are numerous revisions of this chassis/schematic.
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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
undone.evil
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Joined: Sun Jul 14, 2019 4:34 am

Re: 8 Bit Guy CRT TV RGB Mod Log

Post by undone.evil »

now im thinking i should verify the resistors on my tv, i was taking the diagram as gospel. thank you
MarkOZLAD
Posts: 1004
Joined: Thu May 18, 2017 12:39 pm

Re: 8 Bit Guy CRT TV RGB Mod Log

Post by MarkOZLAD »

undone.evil wrote:now im thinking i should verify the resistors on my tv, i was taking the diagram as gospel. thank you
Most definitely.
___________________________________________________
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
undone.evil
Posts: 11
Joined: Sun Jul 14, 2019 4:34 am

Re: 8 Bit Guy CRT TV RGB Mod Log

Post by undone.evil »

i have a few questions if anyone would be inclined to help.

i have modded my trinitron kv-27s42 for rgb with a scart connector and i am trying to make it as automatic as it can be (no switches) so i am using the 5v from the console to send the blanking signal.
i am injecting the 5v after the 1ss133 diode on the blanking line, my thought process is that this diode will protect the control ic from the 5v if the leg goes low and keep it from burning out.

i also noticed that when the console is off and the blanking line is hooked to the television it must pull the jungle chip blanking signal low because i get a black screen and no OSD so i added a 1n4004 diode (this is what i happened to have in my scrap pile) to the blanking line from the console and this fixed the problem.

my question is are these diodes correct for the application that i am using them for or are there better components for what im trying to do. the 1ss133 is a switching diode and the 1n4004 is a rectifier diode.
im not really sure i understand what a switching diode is other than its for low voltage and it is faster.

thank you
zape
Posts: 3
Joined: Thu Dec 26, 2019 5:05 pm

Re: 8 Bit Guy CRT TV RGB Mod Log

Post by zape »

Can you please post the links to the connectors and switches you used?
Do you buy on digikey or ebay?
22r_art
Posts: 2
Joined: Sun Apr 19, 2020 3:12 am

Re: 8 Bit Guy CRT TV RGB Mod Log

Post by 22r_art »

I have a very odd tv that I want to mod.
I have a RCA Secureview J13804CL, I've been trying to figure out how to mod it to RGB, i got the service manual and it looks like a very simple board, i was able to find the RGB out pins on the jungle chip but! it appears that this TV does not have a OSD micro controller. My question is: is there a way to input an RGB signal to the RGB out traces of the jungle chip? or is there any other way to mod this TV? here is the service manual [https://drive.google.com/file/d/1nXztTs ... sp=sharing](https://drive.google.com/file/d/1nXztTs ... sp=sharing)
CrystalJane
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Joined: Wed Jun 03, 2020 4:01 am

Re: 8 Bit Guy CRT TV RGB Mod Log

Post by CrystalJane »

Hi,
I've watched the 8-Bit Guy's 2 videos on adding RGB inputs to a consumer-grade CRT.
I'm interested in doing this to a mid-2000s Disney Princess 13-inch CRT; made by Memorex, model DT-1350-P.
Image
Image
I haven't got it yet due to being out of work temporarily due to the ongoing pandemic, but after I do, this will be my first discretionary purchase, so I'll want to get this project going ASAP.

In addition to requesting a schematic to map out & do this mod properly, I'm having trouble finding what IDC connectors the 8-Bit Guy used in his 2nd video... 10pos, I/O, board mount... I've looked & looked and can't determine a match for myself! Help, someone, please!

Here are the manuals for reference:

User Manual:
https://www.manualslib.com/manual/18844 ... t-DT1350-P
Service Manual: https://www.manualslib.com/manual/90464 ... 350-P.html
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buttersoft
Posts: 383
Joined: Sun Jul 24, 2016 7:49 am

Re: 8 Bit Guy CRT TV RGB Mod Log

Post by buttersoft »

You'd be better off posting in the main RGB mod thread, this is a side topic :)
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maxtherabbit
Posts: 1763
Joined: Mon Mar 05, 2018 4:03 pm

Re: 8 Bit Guy CRT TV RGB Mod Log

Post by maxtherabbit »

I *think* those disney TVs were the same internally as the sponegbab units. The SB TV has a pretty well documented RGB mod
Skbib
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Joined: Tue Sep 01, 2020 3:10 pm

Re: 8 Bit Guy CRT TV RGB Mod Log

Post by Skbib »

Is this work for digital cga signal?
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buttersoft
Posts: 383
Joined: Sun Jul 24, 2016 7:49 am

Re: 8 Bit Guy CRT TV RGB Mod Log

Post by buttersoft »

Skbib wrote:Is this work for digital cga signal?
Nope, it's for analog RGBS signals.
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Bad Company
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Location: Canada

Re: 8 Bit Guy CRT TV RGB Mod Log

Post by Bad Company »

I believe the problem with white-washing, is due to the original RGB signals from the microprocessor being still connected, at the same time as the RGB jacks, so in effect you're seeing the TV's "snow" mixed with your RGB signal. Put a quadruple-pole 3-way switch, in place of the other switch, and use the other 3 poles, to disconnect the original RGB lines, when you're not using them. :wink:
Sometimes, I actually know what I'm doing.
RogerB
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Joined: Thu Jun 24, 2021 1:28 am

Re: 8 Bit Guy CRT TV RGB Mod Log

Post by RogerB »

MarkOZLAD wrote:
undone.evil wrote:now im thinking i should verify the resistors on my tv, i was taking the diagram as gospel. thank you
Most definitely.
Hi, I discovered that my Sharp 20k-S100 CRT television has a 6.8 kilo ohm resistor from the section of the microcontroller and 1.8 kilo ohm resistor from the OSD inline. I'm kind of confused on how do I calculate the resistor value I need to add in OSD RGB input section of the board. Because I used the chart you posted in here of the OSD-Mux-RGB External-Inline-Resistor-Table and I look at the 1,800 ohm resistor value since mines is 1,800 ohm resistor and I saw in the no diode on OSD section "calculated" that the resistor value should be 218 and the Next Standard size should be 220. So I assume that I need either a 218 ohm resistor or 220 ohm resistor. Also it doesn't add up the resistor value of the chart that I will place to get 0.7 volts. I put on the calculator the 220 ohm resistor and instead I get 1.14 Volts. What resistor value should I replace it with? Like does it have to need two resistor or is it okay with like only one. And if I only use one 1200 ohm resistor should I directly solder the RGB wires directly to the OSD input of the Jungle Chip. Because I did the calculation with replacing the 1800 ohm resistor with 1200 ohm resistor and I got 0.75 volts. Thanks in advance

This the service manual/schematics of my CRT television:https://diagramas.diagramasde.com/otros ... 0KS100.pdf
KPackratt2k
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Joined: Sun Apr 04, 2021 11:02 pm
Location: Seattle, WA, USA

Re: 8 Bit Guy CRT TV RGB Mod Log

Post by KPackratt2k »

I just got a 20" Curtis Mathes Tronics CRT TV from November 1999 that appears to have a similar chassis to The 8-bit Guy's TV. One of the differences I see is the jungle chip is a TA1282AN which I haven't been able to find a datasheet for, but I assume it's close enough to the TA1201AN since someone else successfully modded a newer model than the one I have using the same instructions.

Suppose I want to use a SCART connector and use automatic blanking from the consoles via pin 16, what would be the best way to accomplish that? I'm thinking the best way to do it would be to place a diode before R919 (the inline blanking resistor) and running pin 16 of the SCART connector between the diode and the resistor based on the last image on the OP. Does this sound correct or am I missing something?

I know the vias on the mainboard don't correspond to SCART contrary to the AV jacks housing shape, I'm going to remove the AV jacks (the solder broke on them, but luckily the pads survived) and run wires through a straight SCART connector mounted on the back casing in the original spot where the AV jacks were. It's going to be a tight fit since I only have 5mm of clearance between the SCART pins and the components on the mainboard (a few capacitors and a heatsink), but I think I can make it work.

EDIT (8/9/22): I've tested automatic blanking using the method I've described and it worked perfectly. I'm also going to add RCA jacks and a DPDT slide switch for audio breakout while I'm at it. I have some shielded cable that I'll be using to minimize interference from the mainboard components that are close to the SCART connector.
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