RGB to Scart Cable Doesn't work in my Grundig LCD TV

[paulo_becas]

I got an RGB to Scart cable from Amigakit and when i plug it to my amiga and to my LCD TV i get no image, i've read that i need to rewire the cable here http://eab.abime.net/showthread.php?t=50148 but i want an opinion about it before i mess around with the cable.
Can somebody help me out?
Thank's.

[alexh]

If you do rewire it and it does fix the problem please report back.

[DaveGlo]

My scart/rgb cable didnt work either (just a white screen). Have you tried it in all scart sockets? Mine worked when I unplugged the Sky box from scart1 and used that.

[FOL]

Originally Posted by DaveGlo

My scart/rgb cable didnt work either (just a white screen). Have you tried it in all scart sockets? Mine worked when I unplugged the Sky box from scart1 and used that.

Thats because your other scart socket was proberly Composite only, no RGB.

[steve_uktv]

its probably the lead because some tv systems / rgb monitors etc require a pull up voltage that tells the device to switch video mode, i would follow the wiring option you stated earlier....sometimes you can select av mode via a remote on most tv systems but not always (channel 0 usually).

[alexh]

I would be very surprised if the RGB select (1-3 volts on pin 16) was missing on a cable from Amigakit. I can imagine it being the wrong voltage and missing its corresponding ground but it would have to be a very poor cable not to be present.

It is more likely to be either lack of grounds in general. OR the TV video decoder is trying to blend composite video with RGB for a sharper picture.

Ian Steadman said some chipsets do this. The problem is that Amiga SCART cables do not have composite video. They have composite sync instead. This would be fine only the composite sync the Amiga outputs is at the wrong voltage level unless it has an in series resistor.

Lack of grounds and wrong voltage levels rarely affects a CRT TV but seems to play havoc with some LCD/Plasma's.

[hardwir3d]

Originally Posted by FOL

Thats because your other scart socket was proberly Composite only, no RGB.

I've got an RGB-Scart cable aswell. Also shows a white screen only. Even though AV1 accepts RGB input according to the TV's manual. My TV is a Panasonic Quintrix TX-32PM11F.

Any suggestions?

[alexh]

Originally Posted by hardwir3d

I've got an RGB-Scart cable aswell. Also shows a white screen only.

This is usually due to the cable missing the resistor on the composite sync wire and the voltage being too high. The video encoder is trying to blend composite video with RGB video. Just add the resistor and it should work.

See the diagram here :

http://eab.abime.net/showpost.php?p=592491&postcount=1

Add the 75 ohm resistor between pin 10 on the Amiga and pin 20 on the SCART. If that does not work then you will need to add the corresponding ground on SCART pin 17 if it is missing.

[FOL]

Originally Posted by alexh

This is usually due to the cable missing the resistor on the composite sync wire and the voltage being too high. The video encoder is trying to blend composite video with RGB video. Just add the resistor and it should work.

See the diagram here :

http://eab.abime.net/showpost.php?p=592491&postcount=1

Add the 75 ohm resistor between pin 10 on the Amiga and pin 20 on the SCART. If that does not work then you will need to add the corresponding ground on SCART pin 17 if it is missing.

Hmmmm, this isnt always true.
Mine was working for over a year on my tv via Scart 1 (RGB) and then all of a sudden, I got a white screen, and it never worked again.
Didnt matter which scart I stuck it in.

[alexh]

@FOL

I'm not sure about the purpose of your reply? Are you suggesting that he doesn't do anything and just lives with the fact that his Amiga doesn't work with his TV??

Adding a resistor & grounds is easy to do and either it fixes the problem or doesn't.

[FOL]

Originally Posted by alexh

@FOL

I'm not sure about the purpose of your reply? Are you suggesting that he doesn't do anything and just lives with the fact that his Amiga doesn't work with his TV??

Adding a resistor & grounds is easy to do and either it fixes the problem or doesn't.

My point was, it was the scart in my case, but the TV. After I bought my new TV, it wouldnt work in scart 1, but worked in scart 2.

The resistor and grounds should already be there.

[hardwir3d]

Originally Posted by alexh

Add the 75 ohm resistor between pin 10 on the Amiga and pin 20 on the SCART.

Alexh,
Just noticed one of the scart pins (pin 17) is broken off. There's about 1/3rd left of the pin. I suppose this is the culprit or will it transmit the signal anyway?

BTW, there's a 330 ohm resistor between pin 10 and 20 in the diagram, right?

[alexh]

Yes, 330 ohm.