Main > Monitor/Video Forum
How to use SCART for our hobby
ceekay011:
--- Quote from: Zebidee on December 12, 2009, 07:08:30 am ---
--- Quote from: ceekay011 on December 12, 2009, 05:59:36 am ---@Zebidee
what do you find crazy on the cable ?
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Hmmm. I made a mistake in some of my recent posts: SCART 16 is RGB switching, not SCART 18. Very, very sorry about that! It may have probably caused you some frustrations. I think I'll go and edit my earlier posts to fix the errors in case someone else follows them.
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I was a bit wonderd about the "SCART 16 is RGB switching, not SCART 18" ??? but i did read the other post and saw that you made a mistake ;)
1) i will see again if the sync works like you sade in the post
3) 1K i saw it other forum http://translate.google.com/translate?hl=en&sl=it&tl=en&u=http%3A%2F%2Fdigilander.libero.it%2Fventuri1975%2F wood be safer for the tv , doint know if it true
what of interference on the sync do you mean ?
Zebidee:
--- Quote from: ceekay011 on December 14, 2009, 12:00:58 pm ---1) i will see again if the sync works like you sade in the post
3) 1K i saw it other forum http://translate.google.com/translate?hl=en&sl=it&tl=en&u=http%3A%2F%2Fdigilander.libero.it%2Fventuri1975%2F wood be safer for the tv , doint know if it true
what of interference on the sync do you mean ?
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Sync input standards for most SCART TVs is actually 1-5v! It is only the RGB inputs that need to be 0-1v.
Many video cards output sync at close to 4.5 to 5v - it varies a little.
A JPAC fro Ultimarc will actually pull this down slightly, and output sync at around 3.3-3.5v
Pull the sync voltage lower than 3v and you may have problems with your TV accepting the sync signal.
I've tried lowering the JPAC's 3.5v further with a 75ohm resistor to around 2.0 -2.5v, and had problems locking into the sync - the top part of the screen was out diagonally. Tried another TV and got the same result. Tried another TV and it was OK, but harder to sync in. Removing the resistor solved the problems
Key lessons from this:
1) don't put a resistor on the sync in line, because SCART accepts 1-5v already OR
2a) only use a 47ohm or max 75ohm resistor on (which should lower the VGA sync voltage from 5v -> about 3v) AND
2b) use a multimeter & keep part of the sync wire exposed around the resistor so that you can test the voltages while in use.
Kman-Sweden:
--- Quote from: Zebidee on June 03, 2009, 05:36:34 am ---Finally, to access the Service Mode, you must first select program 91 and set "Sharpness" to minimum, then very quickly press "Red", "Green" and "Menu" in turn, then "OK".
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Bloody hell! Does it say "Simon says" in the beginning? ;D
Eversynth:
Hi all. I have a strange problem with my vga-scart cable/TV, and I'm in need of help.
I have 2 TVs, and 2 graphics cards on the same PC.
In the first TV (we'll call this the "BAD TV"), both my arcade PC and my Nintendo Wii are connected to the same scart RGB port, using an adapter. Obviously I have only one device on at any time, the PC or the Wii.
In the second TV (we'll call this the "GOOD TV") my VGA-Scart Cable works flawlessy, with both the first and second graphics card.
In the BAD TV, the colors have a defect I cannot describe. It's evident when looking at the "color bar" in the card properties, under color depth: the color aren't distinct, red green and blue blend: red blends with purple, cyan with yellow, green is faint. Yellow and purple show fine.
But, if I look at the icons on the desktop there's no color bleeding/shifting: red, green and blue look fine on their own.
Now the strange thing: If I connect both the vga-scart and the Wii Scart cable (Wii powered off, not connected to AC adapter), the colors are correct. If I connect only the vga-scart, the colors have the problem described above.
The same cable when connected to the second TV (Good TV) works fine.
So, I investigated what was different in the Wii Scart cable even with the Wii not connected to power, and it looks like Red and Green get between +1,5v and 2,4v, while Blue gets between -1,5v and -2,4v (yes). Those values were misured with my multimeter, using the voltmeter and testing scart pin 17 as ground and the red,green blue scart pins. The other pins don't affect the signal. Only pin 17 acts as ground, the other grounds are not present in the Wii RGB scart cable.
In short, looks like my BAD TV would prefer having a "stronger" colour signal, where the Good TV doesn't care.
Any idea on how to solve this, other than keeping the wii-scart cable connected at all times?
I would change the TV with a newer one, but new CRTs are hard to find and I don't have money. :(
There must be a way to make it work...
Any and all help appreciated.
Zebidee:
We need more information ....
Q1 Exactly how is your VGA-SCART cable wired?
Q2 What brand TVs are we talking about?
Q3 What video card are you using?
I don't think that voltage levels are the problem.
Does the colour work when just the wii cable is plugged in, and not the Wii itself? I suspect the presence of the cable is detected by the TV and it responds by auto-selecting composite for the Wii cable and RGB for the VGA-SCART cable. I suspect that your VGA-SCART cable is not doing this properly by itself.
We need to know how your VGA-SCART cable is wired. So far my guess is that it has something to do with your cable's grounds or perhaps RGB/mode signals. Different TVs have different levels of fussiness about these things.