Saturn RGB scart problem....

[J0e Musashi]

You'll get a flash with the RGB21 cable, but that's it.

[Duddyroar]

davy - I'm watching these developments with interest, as I believe we may have a similar problem...

Have you tried any other TV sets?

[davyK]

I have indeed.

I have tried it on two newer sets. I tried my other main TV at home which is a widescreen TV and has lots of inputs - however I've been having trouble with it and it has been returned for repair for couple of times. On this TV I get a very unstable colour composite picture (tried all 4 input sockets!).

I tried at my parents' house who have a new widescreen TV - on it I get a stable composite picture in colour.

The thing is I got these results with BOTH cables - the one I already have with my PAL Saturn and the one I ordered from Raven......

.......and to top it all, bear in mind that with my PAL Saturn I get a crisp colour RGB picture on my original TV with BOTH cables.

[Duddyroar]

Just to muddy the waters a bit more, I previously bought an RGB cable from Raven that worked fine on my old telly (a quite new Toshiba) and my old Japanese Saturn (white model, I'm assuming the one I have now is pretty much intentical).

I'm going round a friend's tonight and will test the system and cable on his TV set as well.

[davyK]

I'm more or less convinced that this all depends on the voltages sent to certain pins in the SCART socket that put the TV into RGB mode.

Quote from this webpage: http://members.optushome.com.au/evil.../gamescart.htm

"The SCART spec states that to switch to RGB mode the CVBS Status pin must be fed 12V and the RGB Status (aka Fast Blanking) pin be fed 1-3V. Some games consoles only output 5V which may or may not be adequate. .......... In cases where the TV is a widescreen model or has a widescreen mode feature, applying only 5v to the RGB Status pin may force the TV into 16:9 widescreen mode."



My guess is that different TVs require different voltages to switch and some may require too high a voltage that the combination of console and cable will provide.

I don't know if the input to the console in terms of power has any impact (though I doubt it).

I went to the trouble of sourcing a 100v-120v step down transformer (most step down to 120v) as the back of my white console reads 100v. Maybe that has some impact? Unlikely I know but there do seem to be lots of parameters in this situation.....

[Duddyroar]

That makes sense.

My in-laws have my old Toshiba telly so I might test the Saturn on that as well tonight - if it works then I know that my current TV is 100% at fault and then I'll have to find a way round it.

[chaoticjelly]

Hi choaticjelly,

I ordered an RGB scart cable for my white JP Saturn last year from www.ravenonline.co.uk and the site said that it was for both grey and white models. When it arrived it didn't work. I tested it on a pal machine to make sure they hadn't sent a UK one and it didn't work on that either.

I called them and spoke to Jason who told me that very late model white consoles were wired slightly differently. He said he would have to get his engineer to make one up for me. I sent it back and about 3 weeks later got a replacement that worked just fine.

Raven games are definitely not afraid of profiteering and they never have been. They didn't try to charge me anything extra for the 'special' lead.

Do you still have the cable? If so.. please do share the pinout and any colour bands of resistors etc in there..

Eviltim shows the voltage on his site as being 5v. The cables I had were wired up sync as the voltage which measured as 12v. The resistors were appropriate to drop that voltage down. I don't know if the consoles I have are late release or what. I've got a white Sonic Toys 'r' Us Saturn, about 3 white Saturns and a couple of greys and quite a few PAL saturns for spare bits etc.

You reckon the Sonic one would be a late release?

Specifically, not just the voltage matters I believe.. but the current, so the pins need a certain amount of mA to switch.. maybe it is weaker in your Saturns but without any measurements thats purely conjecture.

My first multimeter was about ?4-?5 inc postage off eBay, did the job just fine till I got a more fancy one. These things come with manuals which will probably explain how to take measurements better than I can..

You'll get a flash with the RGB21 cable, but that's it

No they are talking about a European SCART cable, wired up differently i.e. for "Japanese consoles" not an actual Japanese RGB21 cable..

[chaoticjelly]

Ok remembering from electronics at school (oh god)

V = I X R
(Voltage = Current x Resistance)

You can put that into a triangle, with V at the top, and I x R at the corners, with a line halfway through the triangle.

So basically these are the three things you have, if you know two you can work out the other. SO, if we want to know the voltage going to the RGB switching and AV switching pins, we need to take a measurement of the current (I) so that we can multiply it by the resistance (R) (the value of the resistor).

I suppose its feasible that the amps on the voltage could vary between consoles? This would need to be measured..

[davyK]

Looking at a previous post here about the Argos switch block has me intrigued....especially given the progress I made using my existing SCART block. I have just bought one and will try this at home this evening.

Will report my findings. If it works with me just plugging my digi-box and Saturn into it and there's no bleeding of picture/sound then I'll certainly be happy in the short-medium term.

Raven haven't received my cable back yet which I posted Saturday morning (but then posting between England and N.Ireland can be very slow from some baffling reason - I get things from mainland Europe and the US quicker!).

[Duddyroar]

I'd be VERY interested to know if that works mate. I was looking into getting one myself.

[Duddyroar]

I suppose its feasible that the amps on the voltage could vary between consoles? This would need to be measured..

How can I measure this?

This is probably a noob question, but could the type of stepdown converter being used effect this? I only ask because my previous stepdown was different to the one I use now.

[chaoticjelly]

How can I measure this?

This is probably a noob question, but could the type of stepdown converter being used effect this? I only ask because my previous stepdown was different to the one I use now.

Use multimeter & nope wont affect

[gcjae]

Hi chaoticjelly,

You lost me a bit with all the technostuff (!). I will do my best with how it's wired. I'm looking at the pins like this.... (with the pointy bit of the connector on the top left)

_____________________________
\ 1 2 3 4 5 6 7 8 9 10 ]
[ 11 12 13 14 15 16 17 18 19 20 ]

1. White wire
2. 2 black wires (1 from the cable and one joining point 9)
3. Yellow wire with rbeige resistor with banding bronze, black, green, brown
4. Nothing
5. Nothing
6. Nothing
7. Nothing
8. Brown wire
9. Black wire from point 2
10. Purple wire
11. Nothing
12. Nothing
13. Red wire
14. Nothing
15. Green wire
16. Nothing
17. Blue wire
18. Nothing
19. Nothing
20. Nothing

That's the best help I can give as I'm not very technical.

[davyK]

Well the Argos switchable SCART block trick didn't work.

It feels quite cheaply put together though and the picture of anything put through it didn't look too hot.

It is obviously wired differently to the one mentioned in the earlier post.

Back to the drawing board - I'll wait to see what Raven say. Hopefully Argos will take it back ! What I got didn't match the picture in the catalogue (which has a disclaimer about "different styles") so its probably a bit of a gamble buying one as each batch may look different and may well be wired differently.

Ho hum.

EDIT:
It seems I got the crappy 5-in-1 switcher with built-in connector to the TV while the recommended one is a 3-1 with which you have to get a separate cable to connect to the TV. It also has an RGB button and other features - I'll swap the one I got today and try that one (its cheaper too!).

[chaoticjelly]

Thanks for that gcjae, I make that resistor out to be 15 ohms, the colours read with the gold/silver band last (the tolerance). Thats a very small resistance indeed..

The rest of the wiring sounds fine, it would be interesting to know which pin the yellow wire at 3) (with the resistor) was attached to on the 10 pin mini din. Since I mentioned earlier its possible to use the sync line as +12v or the proper voltage-only pin for +5v..

I guess I should get a few Saturns together, make some measurements and record some info into a table.. then analyse.