Amiga 500 rolling picture

[kiario]

Hello. I got hold of a A500 it is great except the picture with scart RGBb is rolling slowly upwards. Picture is superb otherwise. But not usable due to the scrolling. Is it a problem with the RGB out on the computer?

[kiario]

Hi thanks for the reply,

I am using a PAL amiga with RGB scart cable connected to a B&O TV. PC, game consoles work great both 50 and 60hz.

But with amiga the picture rolls.  But not so fast that I cant see the 1.3 hand and disk when turnin on Amiga. The actual picture is great, its problem is that it is scrolling.

I read somehwere that pin 12 is the sync signal from amiga port, perhaps contact problem somewhere.

[kiario]

Thanks, will check pin 19. I have two scart cables and both produce the same result. But I will check.

[kiario]

Hello,

I checked the cable and there is nothing connected to pin 19 and 20. So there is no sync? Strange, the cable is bought from a Amiga retailer. BR Anders

[kiario]

Thanks, well there is nothing connected to 19, 20 or 21.

I went ahead and ordered a cable from Amigakit. Hopefully it will work.

On RF mod I the problem does not exist, however quality is awful.

[kiario]

B&O = Bang & Olufsen best CRT TV manufacturer there was.

There is no adjustment for vertical hold. I'll check the service setting but I doubt vertical hold is one of them.

[kiario]

Hi,

I have the A500 Rev 6 board. Is it possible to softswitch without jumper?

For now I think my scart cable is not correctly wired.

The TV automatically switches between PAL/NTSC.

I also have a eee pc connected to the TV via scart/s-vhs and video box without issues.

Regarding PAL vs NTCS, I actually prefer the PAL image even though NTSC is less flickery. Actual image quality is more intense and colours are better in PAL.

[kiario]

Some more info after much investigation. My conclusion is that the scart splitter I use is causing the issue. If I connect the Amiga through the splitter(quality splitter sold on amikit) the screen rolls for the first 15 minutes or so then gradually stabilizes. If I connect the amiga directly to scart on TV it syncs immediately. So the splitter is probably "eating up" the signal in some way.

[kiario]

I am sure it is not a fault with the splitter since I have a dreamcast, SNES and megadrive connected through it without problem. Sync issue only with Amiga connected to the splitter.

There could perhaps be some kind of compatibility issue with the splitter and amiga. Maybe the signals from the amiga are very weak and absorbed by the splitter. Or the splitter is not wired to function 100% with amiga.