RGB to SCART cable problem

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Mamejay
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RGB to SCART cable problem

Post by Mamejay » Sun Jun 30, 2019 6:51 am

Hey everyone,
I made myself a RGB to SCART cable for my model B but I am getting what looks to be a sync issue. I have used an old VGA cable
I followed a diagram from mdfs.net site

Here is a link to the youtube video of the problem
https://youtu.be/moIR0GEru8o

I have checked all connections but not sure what is going on. I am in Australia so SCART is not common. Do I need to attach the all the ground lines for the RGB or is it ok with just the single one in the diagram?
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Scarts.gif

stephen_usher
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Re: RGB to SCART cable problem

Post by stephen_usher » Sun Jun 30, 2019 9:45 am

Myself I would connect all the signal ground pins to ground in case the TV itself is balancing the signal relative to their own ground pins.

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1024MAK
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Re: RGB to SCART cable problem

Post by 1024MAK » Sun Jun 30, 2019 11:31 am

Have you tried on more than one TV?

It could be that the TV is getting confused by the slightly non-standard TV signal from the computer. If your TV has a menu control to manually select the TV system, select PAL 50 Hz and/or system I (that’s an upper case i not a one).

It may also be a problem with the automatic switching system in the TV being unable to decide if it should be in composite mode or RGB mode.

On your remote, or in the menu system, see if there are any manual controls to select SCART RGB input.

If not, try the suggestions in this post.

Mark
Last edited by 1024MAK on Tue Jul 02, 2019 9:36 am, edited 2 times in total.

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SpaceFlightOrange
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Re: RGB to SCART cable problem

Post by SpaceFlightOrange » Tue Jul 02, 2019 8:34 am

What Mark said.

I made one based on the instructions on MDFS.net and on my nice 32” Sony the picture kept blanking (like yours, but without the picture jumping) and resetting to 16:9

I disabled the auto switching which solved the aspect issue but couldn’t fix the blank.

I ended up using a cheap old 22” instead. Picture is rock steady.
James

BBC Model A Issue 3 (Upgraded to Model B, had it since I was a kid), Opus Dual 40/80 FDD, Watford Mouse, Voltmace delta 14/B, Gotek, IFEL ROMRAM-B4, Pi-Zero CoPro

Master 128, VideoNuLA, Gotek

Mamejay
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Re: RGB to SCART cable problem

Post by Mamejay » Tue Jul 02, 2019 11:20 am

Thanks for the advice. I have one ordered from cool-novelties on ebay in the UK.
Hoping this will sort it out.

Just a question. Would the composite colour fix jumper have anything to do with it?

cmorley
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Re: RGB to SCART cable problem

Post by cmorley » Tue Jul 02, 2019 11:26 am

It really is hit and miss as to if the TV will handle the BBC sync or not.

I have several LCD TVs here. Most don't work with the BBC properly but work fine with other retro computers. I have one Samsung which does, one Samsung which does but drops it on MODE every so often and a Tesco Technika which goes blank for a few seconds regularly. My old Pioneer Plasma works fine. (I have 3 different SCART leads - same behaviour with each lead)

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1024MAK
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Re: RGB to SCART cable problem

Post by 1024MAK » Tue Jul 02, 2019 2:20 pm

Mamejay wrote:
Tue Jul 02, 2019 11:20 am
Thanks for the advice. I have one ordered from cool-novelties on ebay in the UK.
Hoping this will sort it out.

Just a question. Would the composite colour fix jumper have anything to do with it?
IIRC the cool-novelties SCART leads and the RetroComputerShack cables have the same wiring (see other post).

The “colour” jumper in the Beeb only affects the composite video output (BNC connector), not the RGB (DIN socket).

Mark

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