PS2 RGB SCART question

Started by Zaarin, June 19, 2004, 12:34:11 AM

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Zaarin

Hi.

I recently bought an RGB SCART lead for my PAL PS2 to connect to my 16:9 TV. However, when I tried to play the TV itself locked into 16:9 mode making everything look stretched.

I opened up the SCART plug and noticed it had a wire going to pin 8 with a resistor going to pin 16. I found out from some schematics that pin 8 is for RGB/16:9 switch. (seems like every site has a different name for the pin) so I simply disconnected the wire. When I turned the TV back on, it was in 4:3 mode, but it couldn't get the RGB signals. It showed the picture from the composite signal (I can't choose RGB manually on my TV).
The only thing I could find on pin 16 is that it is a blanking signal (what the heck is that?) and some site said RGB as well. I cut the resistor off pin 8 and soldered it to the loose wire. When I turned the TV back on, it finally worked.

The plug looked something like this:
http://www.rgbcube.co.uk/image010.jpg

Later I measured the current on the wire going to pin 8 and it was 5V. According to one of the sites I previously visited, if the current is between 5V and 8V, widescreen TVs will switch to 16:9 mode.
Why do they add 5V to pin 8 when the plug works without? What's the resistor for and can it hurt the TV that I disconnected pin 8 like this?
I'm just a little confused, there's a lot of sites with SCART pinouts, but not many care to explain how the inputs really work...

NFG

#1
This is a problem with the SCART spec, no one seems to know how it really works, it's compounded when people like me (who own no PAL equipment) don't really care.  ;)

The pins in question are used to tell the TV what mode to switch to so the user can be lazy, but what often happens is one TV will do things one way and another will do it differently, and the little kids in hongkong making your SCART cable are wiring it up for neither of those two TVs.

Endymion

To the best of my memory, "blanking" is just tied to ground, for what purpose (along with that resistor business) I have no clue as I don't have a SCART TV. I do use SCART connectors, since the cables are cheap and plentiful. It sure would be nice if it were a world-wide thing. However, the more I read SCART questions and hear testimonials about different modes and how the thing is wired up and such, the more I seem to understand why an electronics manufacturer might not want such an open-ended standard for their product. Nobody wants their customer to be confused. :mellow:

Zaarin

#3
Well, this site lists blanking and blanking ground as two different pins: http://www.diyha.co.uk/electronics/scart.html
I also read that if blanking is 1-3V, the TV will switch to RGB instead of composite. Sounds like pin 8 is there only to confuse the hell out of my TV :)

Martin

They are two different pins.
But inside the plug they are both connected to the same wire.
[span style=\'font-size:14pt;line-height:100%\']barenakedladies[/font][/span]

Hojo_Norem

From my experience, pin 16 selects between composite / s-video and RGB.  Most SCART tvs will switch to RGB when a voltage is applied, however not all TVs (especialy older scart ones) will not switch properly to scart, resulting in a garbled rolling picture, switching to the scart manualy will fix this.

Pin 8 as I see it has 2 functions, firsly to force the tv onto scart and secondly, depending on the voltage applied (I think) selects 4:3 or 16:9.  Some 4:3 tvs (mostly newer ones) will switch into leterbox mode when 16:9 is signaled.  This is preferable to setting your equipment (DVD, set top DTV reciver, etc) to letterbox mode, as when the TV is in letterbox mode, all the lines are drawn, resulting in a sharper picture, while a DVD player in letterbox mode achives its effect by skipping lines to get the ratio right.  
Formerly 'butter_pat_head'