I have just bought the new Pi 4 4GB and I’m powering it with my old 2,5A official pi3 power supply and a usb-c adapter. The red LED turns on and the green LED blinks, however neither my set-up Buster system or a fresh install on a SD card are showing anything on a HDMI monitor (through the official HDMI adapter) on ports 0 and 1 or are connecting to the wired network.
I am flashing the official Raspbian Buster image using Balena Etcher.
Could it be a problem with the Pi?
Edit: I removed the FAN Shim I bought with it and everything worked as expected… Why would the Shim interfere with the bootup?