So I thought I had better post to say that I solved my own problem. I had to get sync from SCART pin 19 on the Pi2SCART's female connector, not pin 20. I did not know about male SCART leads swapping pins 19 and 20. I hope this post might help somebody else out one day.
Sudo bash ./set_video.sh They won't turn on. I uploaded the scripts to a pendrive. Raspberry sees these files from position F4 but these commands cannot be turned on.
I'm not familiar with those scripts, don't they have any documentation attached ? Try copying them first locally, on the SD card, instead of trying to execute them from the USB drive. After you copy them, make sure they're executable - run chmod +x <file_name> beforehand.
@Efriim It is possible if you feed it some outlandish timings. I am not saying the ones you have posted will do that, they may well work OK, but not knowing the source and what they were intended for it's hard to say. I'm talking about the hdmi_timings ones, these can be dangerous. The config.txt is good, but I would skip the ones from your post starting with hdmi_cvt.
I'm bit busy now but will post my confirmed-working settings (for a CRT TV though) later. In any case OP should try the arcade forge image first, even if just to copy the configs from it to the official Retropie.
EDIT: my old config.tx. You can also try the "AF" and "mohl" settings (just make sure to remove #AF for example)
This should give you a stable picture, I have used these settings on many CRT TV sets, they should work on a monitor too I think (or at least won't damage it).
problem is, this will only work for few emus in 1:1 scale, since they often used different resolutions. To handle this you need to use the high-res trick (read the thread I linked to)
For that you need to change the runcommand and then also adjust the settings in retroarch.cfg (custome aspect ratio and resolutions, or use integer ON/Off option). Unfortunately I'm not near my SCART TV sets and can't remember all these settings exactly so can't help you here. You either use the Arcade Forge image, figure it out from the resources here or post on reddit in /r crtgaming sub.
I also have the pi2scart ouputting on a 28 inch consumer crt from philips and dont have those "problems". I cant even take photos of my scanlines becaues they are so subtile. Would like them a bit more beefy to be honest but its not that easy to get a pro crt here sadly.
@simonster I have a NTSC set, With component it's the reason I'm using the YUV Transcoder all my other consoles is using Scart cables via a Scart Switch. Some how I eliminated the squeeze picture issue and ran into other problems with Retroarch not saving menu settings. And I can't get cores to run at all. I would down load them but they will not show up.