Which scart pin contains +5 volts from consoles?

[LucidDefender]

Using an RGB scart cable on systems like the Genesis, SNES, Saturn, etc, which pin on the scart connector will the +5 line from the console go to? I know the wire often has a resistor on it before it hits the pin to drop the voltage, but which pin actually carries this voltage? I have a few SCART cables for systems that I'm going to put a DB9 connector on, but the SCART pinouts are kind of vague on which pin carries the +5 voltage.

Thanks guys!

[NFG]

The wiki to the rescue:

http://gamesx.com/wiki/doku.php?id=av:scart2rgb

[viletim!]

Lawrence, there are lots of errors on that page.

"Some displays, especially those with TV tuners, require composite video, and won't function with composite sync instead. This is the exception, not the rule."

No SCART socket is designed to accept a TTL composite sync signal. This is strictly a composite video input and should always be connected to the composite video output of a console. As all consoles output composite video, there's no reason to 'dodgy it' by hooking up composite sync.

"I used +5v for blanking, but you may need to use a 100Ohm resistor on this line."

That's not such a good idea. The blanking line is 75 ohm terminated, just like the video ones. If you apply any voltage higher than 3v you're in danger of overheating the termination resistor which is usualy only rated at 250mW. A 100-200 ohm resistor should ALWAYS be used in series.

"Ground is Ground, you don't have to use separate wires from end to end. One ground line is enough, but you must connect ALL the ground pins to each other on each end."

Actually, connecting all the ground pins together isn't necessary (at least at the SCART end). Just connecting the ground to pin 17 (CVBS ground) is good enough. Though it's not a bad idea to connect a few more - a good ground connection is important. The extra ground connections are mainly provided for convenience when using coax/sheilded cable for a/v signals.

LucidDefender,
If the console has a +12v output then you can connect it to pin 8 of the SCART so it will automaticaly switch the TV into A/V mode.

[NFG]

viletim: And have you changed the wiki page yet?  =)

[Midori]

"Some displays, especially those with TV tuners, require composite video, and won�t function with composite sync instead. This is the exception, not the rule."

No SCART socket is designed to accept a TTL composite sync signal. This is strictly a composite video input and should always be connected to the composite video output of a console. As all consoles output composite video, there's no reason to 'dodgy it' by hooking up composite sync.

They don't accept composite sync signals? O.O Mine sure does, all of my 3 scart TVs does, or am I incorrect when I claim that my arcade boards outputs composite sync and not composite video?

[NFG]

Most SCART TVs will accept composite sync, I've never seen one that won't.

As for ground, a lot of TVs DO require extra grounds - perhaps not all, but you never know which is required.  It's a good habit to get into - connect ALL your grounds.  It's quick and easy, and you'll never end up with - as I have - a situtation where something doesn't work for silly reasons like this.

[LucidDefender]

Guys, I'm not using a SCART TV I'm using Lawrence's custom DB9 connector pinout. My Neobitz Component transcoder requires +5 volts and is in my supergun, but I'd like to power it without the supergun's power being on. I wired all the wires from a SCART MD2 cable to a DB9 connector, but with the genesis 2 on, all the wires were reading 1volts from my friend's multimeter on the automatic AC/DC setting, which didn't seem right. Also, another time they all read 6 volts, which didn't make sense, so I don't know what's going on.

I don't know for a fact that the SCART cable is passing everything I need, but finding DIN-9 and DIN-10, and super nintendo plugs with all the wires connected isn't a trivial task.

[viletim!]

Lawrence,

Most SCART TVs will accept composite sync, I've never seen one that won't.

A composite video signal (with no video on it) and a composite sync signal arn't too different to each other. Whether it will work or not really depends on the source, not the TV. The mega drive 2 is a good example of a console that doesn't like a 75 ohm resistor tied to ground on it's sync line.

Why connect composite sync to a composite video input at all? Why would you even consider it if you had composite video available?

As for ground, a lot of TVs DO require extra grounds - perhaps not all, but you never know which is required. It's a good habit to get into - connect ALL your grounds. It's quick and easy, and you'll never end up with - as I have - a situtation where something doesn't work for silly reasons like this.

I don't believe you. Every 3rd party SCART i've opened up (not for fun...the damn things are always breaking, wired wrong, etc) has only had pins 17 and 18 grounded (at most). It's ok not to wire up every ground on a SCART cable.

viletim: And have you changed the wiki page yet? =)

I don't know what this crazy adaptor thing is for. So I though I'd better leave it alone.

LucidDefender,
You won't be able to power anything from the blanking line because of the series resistor. You'd have to take it out. It's likely that the reason you weren't able to measure a voltage on any pin was that only one or two grounds were connected in the SCART cable and your meter probe wasn't on one .

[LucidDefender]

I cut the end of the SCART connector off and am using the bare wires. There was a line going into one of the pins, and then a resistor going from that pin to another pin. So it looked to me like +5 was going to one pin, and a resistor was dropping it down for the other pin. I removed the resistor of course.

[Midori]

The mega drive 2 is a good example of a console that doesn't like a 75 ohm resistor tied to ground on it's sync line.

Why would you tie a resistor to the sync line? On my consoles where I use scart, all of them put the picture a bit to the left so a black vertikal border shows on the right side, does a resistor correct this?

And acording to this page: http://www.diyha.co.uk/electronics/scart.html pin 20 is for Luminance input, composit video and composite sync. Not just composite video. Why lawerence should use composite sync if composite video is available you ask, why shouldn't it be the other way? If any if them would be worse I would say its the video line and not the sync line for sync in a scart cable but I havn't noticed any real difference. And if I only connect the sync line from my CPS2 arcade board to RGB scart I will get a picture, but it doesn't contain any colors, just black and white.

edit. Now I remember that I got the black and white picture when I forgot to connect the 5 V to the scart cable for it to switch to RGB mode.

[viletim!]

Midori,
The 75 ohm resistor I was refering to is the termination resistor inside the TV/monitor. The signal you apply to pin 19 should be the same as you apply to a video in phono socket because the two are electrically identical. I've never heard any refer to the typical three phono socket inputs as left, right and sync

Yes, that webpage is correct in that you can composite sync to the VIDEO input but it's not the TTL composite sync that you're familliar with. When you remove the all the picture information from a composite video signal you're left with just the sync information. And that's the kind of signal they're refering to. The only game console I know of that generates this type of 'composite sync' is the dreamcast when set to RGB mode (comes out the video line).

Here's a much better page about the SCART input/output.