I am a beginner with Pi. I got a Pi4 with 4GB ram and Rasbian Full Desktop installed, SenseHAT attached as well. I did the wpa_wifi config file and it works fine, will connect to WIFI with Monitor attached.
When I try to boot Pi4 without HDMI monitor plugged in, the RED power light and SenseHAT board is on but it won't boot. When I mean it won't boot, I mean the Pi can't connect to a network and I couldn't ssh into it via another PC on the same network.
If I boot first and then immediately plug HDMI in 1 second later, it still won't boot.
If I boot with monitor ALREADY plugged in, it works fine, WIFI will connect automatically, can ssh, even I unplug it later, it still stays good.
Also when my Pi successfully boots with monitor, the SenseHAT board will switch off blank which means it's booted. When I boot without HDMI monitor, SenseHAT stays on colourful led lighting which means it didn't boot....
So my conclusion is that it won't boot without HDMI cable connected to a monitor.
Because I am trying to make headless ssh connection available when I am outside.
Anyone can help?