RPi2 doesn't load without HDMI cable

Hi,

I tried to setup my spare RPi2 to use on my old CRT via AV-Out. Installation worked fine. The filesystem is expanding and I get the libreELEC splash screen. But after that I only get a black screen and nothing more. It doesn't even initialise a network connection. If I connect the whole thing to another TV via HDMI it works fine. Having no video cable connected results in the same problem.

I've also tried different power supplies, including the one I currently use for my RPi3 setup, with no success. I'm starting to go crazy and hope someone can help.

Thanks in advance

Thanks for the link, I already read through it before, but it doesn't address my problem. I have the right cable, otherwise I wouldn't see the LE splash screen. I've set the sdtv_mode option as well. Overscan is also not a problem. The problem is that it doesn't boot past the LE splash screen when connected via composite A/V. All I get after the splash screen is a black screen.

My RPi3 works fine with the RCA.

When I connect HDMI and A/V the HDMI works and no signal on the A/V. Also tried just having the HDMI cable (no TV on the other end) attached to the RPi. I don't know how you can switch from HDMI to A/V while the RPi is running. Is that even possible? I thought the RPi decides on boot if the A/V out is turned on or not, depending on if there's an HDMI connection?

Thank you for trying to help. I've checked if the cable was completely in all the time, believe me