RGB modding a CRT- Tips and Tricks without a service manual?

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Tengugurl
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Joined: Fri Jun 07, 2019 2:25 am

RGB modding a CRT- Tips and Tricks without a service manual?

Post by Tengugurl »

Hi there!

New to the forums here, I have heard there are some pretty smart CRT gurus on here and I am hoping I could learn from you all! :)
If you could help nudge me in right direction I can catch on pretty quickly :) (Promise no super noob questions without researching stuff)

Anywhoo....

I am looking to RGB mod (via SCART out) on a USA Sony Trintron KV-13VM42.

Quick question:
1) Where the heck do you find service manuals if your search results are coming up empty?

Background: I am looking for a service manual so I can see the pin-out on the Jungle Chip to identify my Blanking, R,G,B, 5v and possibly a separate Composite (Sync) location
Issue: It's no where to be found on the interwebs!!???
Question: Does anyone know where I can find a similar chassis monitor manual or more ideally a manual for this model? (I can only find user manuals)

2) I have heard that resistors and capacitors should be added to the SCART out to darken/ improve the image once you have found the RGB signals on your TV.
Question: Is there a previous post you could direct me to that shows the right resistance and Mfs I should be adding to my SCART out? (Might be a good question once I find the RGB on my jungle chip lol)

Thanks so much everyone in advance!
Can't wait to learn from you all
Tengugurl
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Syntax
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Location: Australia

Re: RGB modding a CRT- Tips and Tricks without a service man

Post by Syntax »

Ask in the TV RGB mod thread
viewtopic.php?f=6&t=56155&start=2520
MarkOZLAD
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Joined: Thu May 18, 2017 12:39 pm

Re: RGB modding a CRT- Tips and Tricks without a service man

Post by MarkOZLAD »

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

Re: RGB modding a CRT- Tips and Tricks without a service man

Post by MarkOZLAD »

I501 is your jungle TA1268N. RGB into pins 5,6 and 7. Blanking into 4. This should be a candidate for the OSD/External RGB Mux method. RC506, 507 and 509 are the resistors you will want to remove. There is a custom OSD chip, IC702. There are diodes on the OSD lines. Need to work out the resistor values RC734, 736, 737, 506, 508 and 510 to use the lookup table for the Mux resistors.
___________________________________________________
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
MarkOZLAD
Posts: 1004
Joined: Thu May 18, 2017 12:39 pm

Re: RGB modding a CRT- Tips and Tricks without a service man

Post by MarkOZLAD »

Oh, Sync into AV.
___________________________________________________
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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Tengugurl
Posts: 11
Joined: Fri Jun 07, 2019 2:25 am

Re: RGB modding a CRT- Tips and Tricks without a service man

Post by Tengugurl »

Hi!
Wow, thanks so much @ MarkOZLAD - such a thorough and thoughtful reply. :)

I had a look at the IC and you were totally right at the pinout.
I was curious about it saying fast blinking but you just confirmed it for me, you rock!

Thanks so much to everyone who has replied so far.

Quick question,
I have seen people wire up SCART panels (for ease of buying cables instead of standard RCA Jacks and hacking up cables to work on the TV) and I have seen them attempt to get a better signal/ dim the OSD a bit by adding a cap/resistor on the RGB GND signals, have you heard of this?

If you have, do you have a standard rating for caps/resistors that would work?
( Bet I need to match it to the chassis - time to research more)

Thanks again!
Made my night
Tengugurl.

Ps. I will have to check out the RGB forum listed above.
Glad to have a new community of fellow enthusiasts, here!
MarkOZLAD
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Joined: Thu May 18, 2017 12:39 pm

Re: RGB modding a CRT- Tips and Tricks without a service man

Post by MarkOZLAD »

I use the OSD/External RGB Mux method as shown in my signature. I don't change the factory caps or add new ones.

I have wired scart/RCA and BNC on different sets. It's a matter of taste and requirement.

For the Mux method we need to calculate but a rule of thumb is to look at the grounding resistors on the factory OSD RGB lines and subtract 75. On your set the factory OSD ground resistors are R505, R507 and R509. They are 560 Ohm on your set. 560 - 75 = 495, next standard size up is 510 Ohm.

Unfortunately these are surface mount "CHIP" resistors so you will need to have a bit of thought about how you'd implement your mod. Can't use the twist method like I got the 8 Bit Guy to do in his 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
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