A while back i had video problems with my Sprinter. After getting a new mainboard the problem of very dark picture is still there on the TV sets i've tried. Some TVs seem to handle it well. Earlier i heard mention that the russian TV standard is almost like PAL or SECAM.

Would it be possible to use an external circuit to improve the picture on a normal european PAL TV by amplifying the rgb signal somehow?

"Some TVs seem to handle it well."

So you got a good picture with colours and everything on some TVs with your mainborad?

To everyone else I should say that I have the same problem...

I had the same problem. I think again that problem live in SCART connector. I reread old thread about your problem and see new SCART description from PetersPlus. I saw a problem:

Pin 8 must be TV/AV switcher and by official SCART description is 0-2 V (logical "0") for TV and 9,5-12 V (logical "1") for AV. BUT, in PetersPlus scheme we see resistor 300 Ohm from 5V, so it's less than 9,5-12V. We need to have 12V power source. In another description I saw
High (9.5-12V) - AV mode
Mid (5-8V) - Wide-screen
Low (0-2V) - TV mode
And we again need 9,5-12V !!!

Pin 16 "Fast Switch RGB/Video" looks good. 1-3V (logic "1") for RGB and 0-0,4 V (logic "0") for Video. So, we have 300 Ohm resistor from 5V. It's Ok!

I found webpage about connection Amiga to TV through SCARThttp://tis.ihed.ras.ru/books/hwb/ca_AmigaScart.html

And I read that +12V pin 16 Blanking (Connect via a 150 Ohm resistor)
+12V pin 8 Audio/RGB switch (Connect via a 1 kOhm resistor)

So, I think that problem of your TV connection is pin 8!
And I can test my remade SCART connector and write exact mention.



Alexander Shabarshin (shaos@mail.ru)
http://www.shaos.ru

Different TVs have different SCART implementations. There are devices that need switch signal. There are devices that do not need switch signal. So, with PetersPlus SCART you will have dark picture on the fisrt TV and excellent picture on the second TV.


Alexander Shabarshin (shaos@mail.ru)
http://www.shaos.ru

hmmm, So you say it's need 12 v with 150 Ohm resistor to pin 8?
But there isn't 12 v pin from video output connector on Sprinter, or is it?

I am very bad at this electronics stuff, so how can I fix it? Do you take external batterie for extra voltage? :)

> hmmm, So you say it's need 12 v with 150 Ohm resistor to pin 8?
> But there isn't 12 v pin from video output connector on Sprinter, or is it?

Yes, it's true :(
I saw my Sprinter-SCART connector - I have only pin 16 without any resistors and not connected pin 8. May be needed decrease resistor or exclude it. May be pin 8 don't play main role in this problem.


Alexander Shabarshin (shaos@mail.ru)
http://www.shaos.ru

Above, Shaos described a problem (thank you, Shaos, again ).
Yes, Sprinter's video connector hasn't 12V. But too early for despair.
So, we should know which SCART mode (TV mode, Wide mode or AV mode) your TV uses. What model of TV do you use? Maybe we will found information for your TV. Maybe you needn't 12V for switching of SCART mode.
Another solution may be step-by-step increase of a voltage on 8 pin. Maybe threshold of switching will be low.
At first, probably, try to set 150Omh resistor to 8 pin.
BTW, Sprinter's video cable has 390Omh resistor, not 300Ohm. It is not so different. But 390Omh and 150Omh will be more different. Maybe video will be better.

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PETERS PLUS LTD

Doesn't the AT power supply have +12v lines?
Provided you were very brave, you could perhaps draw 12v from the motherboard power connector.
Well... it's a thought =)

hehe, i am not brave enough :)

but what do you think about external battery. could it work? or would i f**k everything up as usual... ;)

Maybe, also from free HDD power connector of AT power supply. Usually yellow wire has +12V, but test of it will be a better way.

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PETERS PLUS LTD