RGB mod for TVs.

This question is directed at Haunted360. I watched his video on YouTube about RGB input mod for a cheap CRT TV. I have a Toshiba one. Model #20AF41. I also have the repair manual for it. Any ideas on how to go about it before I start poking around inside and risk getting defibrillatored with that flyback coil? Also gonna try it on another one eventually. It's a huge mutha f@$^a CRT TV. I'll get model of it up later.

I found this much out already. This TV uses a Micon Tuner that puts out an OSD_R/ OSD_G/ OSD_B/ and OSD_ BLK signal to a Chroma/If circuit that is in charge of video processing. The OSD signals are fast blank ones. How hard would it be to interrupt the tuner signal for my own RGB input as long as the TV is set for the tuner mode? (Like setting it on channel 3 if I'm following diagram right.) What do I do with OSD_BLK? Send a C_SYNC signal or composite video signal to it? Connect VCC? What? Any help would be appreciated as I'm sure there are others out there who would like their NTSC TVs to have RGB input as well. This is for those who prefer their CRT tubes over LCD and plasma panels (NES Duck Hunt competition anyone?) or if they're too cheap to get a TV with RGB SCART input. (Like me. :tongue

EDIT: I have the manual. Here's the location: http://www.encompassparts.com/shop/research_new/TBA/20AF41.pdf

 

Last I heard he didn't get it to work. I got it working on a TV of mine but the colors were all wrong.

 

http://www.youtube.com/watch?v=W3c3F-tY7Mo

He forgot to ground the Megadrive/ Genesis to the TV PCB.

 

This can only end badly.

 

0_o

:nightmare:

 

Bad_AD84 is right. If you dont know what you're doing, then things will end up bad.


I did not add the resistors as shown in 133MHz's blog. I just tied the +5v to the AV's ground which I then believe just used the internal resistors.

I fried the TV eventually, by trying to re-assemble the TV with an RS232 port (for the RGB). I believe I wired the +5v to the wrong pin
I can fix it, as I think I only fried a transistor, but it will be hard to track down and I cant be bothered.

Just follow 133MHz's guide he wrote.
Whenever you work on the TV, dont mess with the flyback or tube and MAKE SURE IT IS UNPLUGGED. Any big capacitors, watch out for them and dont short them with your fingers.

 

133MHz's site does not have the page linked in video. HOWEVER, based on what was said in video, my studying of the repair manual, (which has the IC chips, ID numbers, and wiring diagram) and my understanding of it all, I'm confident to dive into this. TV was found by dumpster so if it fries, no loss. As for the getting shocked part, well I've had my fair share of jolts. Enough to the point that I'm extremely careful around anything with AC current. Same way with DC after I got a massive shock from a welder in the DC mode. 160 amps of 20 volt DC current is not fun. Only reason I didn't fry was because it went from my left hand to my left leg missing my heart. I know I got the full juice or close to it because of the humming it made when dragged down like it does when using full power. (Yes that welder is still around and I still use it with extreme caution.) Also been shocked many times by those capacitors from disposable cameras with the built in flash. In other words, I know what I'm doing around dangerous current from those mishaps. Never trust a known insulator. They don't always do their job. And I will unplug the TV for like a week before I go into it. The other one I'll do next has been in storage for years so no worry of current there.

 

Wow. Sounds like you have had your fair chance of shocks. You're very lucky :S

Unplugging the TV (CRT) will not discharge the tube.

You need to do it manually. There is no need to remove the anode cap on the neck if it is long enough for you to work and you know you have discharged it.
Personally, I did not discharge mine because I was very careful to not touch it, but you may want to be on the safe side knowing your luck may run out.

 

Those caps are weak.

240v from the mains here is weak too in comparison to whats in the back of a CRT.

 

Wow I'm lucky I didn't kill myself a few years ago, had a CRT stop working, took it apart and had a look, no discharging or anything haha, I guess it must've discharged as it died or I was very lucky. In that video, is connecting it to the metal frame really the best way to do it, could you not jam the cable into the earthing socket of a mains plug? (not that I'm planning to do it, but it would be nice to know in case I lose the will to live and decide to re-solder the loose scart sockets on my two TVs)
Also unrelated but is he wearing pjamas in that video? because it looks like he is

 

I dont think you can earth the flyback. You want to short it.

I believe he is wearing pyjamas... and a pink glove :3

 

Don't you usually do all your modding in pink fluffy slippers?

 

Oh right I understand.

To be honest actually I end up doing a lot of modding in my pjamas, I'm too impatient to get dressed first so I just get out of bed and get stuck in lol

 

Same... No time dress. Fix now TV.

 

Didn't realize this would become a popular discussion. My hope is to get everyone who has some know-how in this area to share and maybe this can become a self help for those brace souls who will risk high voltage flyback and capacitor shocks to get better video signal to their aging sets.

 

OK, I've said it before and I'll say it again... if you're not a trained television engineer, DO NOT OPEN A TELEVISION! They're lethal.

As for discharging, you do it to the chassis. Never, ever connect the tube to earth. Such a comment suggests a poor knowledge of basic principles of electricity. You're not earthing it, you're equalizing the charge between the two plates. The correct method is to connect it to the chassis with the machine completely unplugged. Some monitors (mostly vector) require an HT probe so you don't damage it.

 

Heyyyy calm down I'm not an idiot, I was just misinformed and half asleep in this particular instance, someone mentioned it on the internet somewhere when I did some research after the last time one of these posts popped up. Not that I've ever tried it or ever intended to do so because despite you clearly thinking I'm an idiot, I do in fact realise how dangerous poking around inside a CRT tv can be.

 

Buy an arcade monitor. They exist up to 33 inches in crt and add some speakers. Less expensive, less dangerous, much easier.

 

They run at a different frequency. Wont work.

 

Not always the case, although some might need a separate Horizontal and Vertical sync feed (see >here< for info and circuit). I think the arcade monitors use a large isolation transformer so they are relatively safe.
Another option is a Professional Video Monitor from the likes of Sony, Panasonic, JVC, NEC, Barco, Ikegami etc.

Like others have said, I don't recommend the TV mod. It's really easy to be caught off-guard, and with some TV's they have an entirely live chassis which will fry you and your console at the same time.