I do not get any signal from hdmi output 0. When I touch the cable close to the hdmi port on rpi4, the picture appears, but colors are wrong, like if there are issues with contacts.
I have both RPi3 and RPi4. I created a new SD card with the Raspbian Buster. Booted on RPi3 - it was fine. Switched the SD into RPi4 - no video signal. I tried both HDMI ports on the RPi4, I changed the configuration file:
But this didn't help. Also the RPi4 booted and connected to wifi as I could see it in my network and I could ssh to it. So it tells me there is no issue with booting. The only case when image on display appears is when I put some pressure on the hdmi cable close to rpi4 micro hdmi port.