https://support.thepihut.com/hc/en-us/articles/360001887937-My-Raspberry-Pi-4-will-not-boot
Sorry to hear that you're having troubles with your new Raspberry Pi 4.
All Raspberry Pi's are tested before they leave the manufacturing factory in Wales, so a faulty Raspberry Pi is quite rare.
Below are the most common reasons for a Raspberry Pi 4 not to work as expected:
- Wrong HDMI port - The Raspberry Pi 4 has two HDMI ports (seen below). The connector on the left marked "HDMI0" is the primary display, so you'll need to ensure this one is always plugged in.
- Operating System- Only the latest operating system release will work on the new Raspberry Pi 4 (at time of writing NOOBS v3.1.1). This will also need to be a fresh install, not used with a previous model of Raspberry Pi. Your options are..
- Grab a pre-installed MicroSD card from our store
- Use 16GB (32GB or higher seen have problem)
- OR download the latest operating system from the Raspberry Pi website
- Power Supply - The new Raspberry Pi 4 needs more juice than previous models - You'll need an official 5.1V 3A power supply (or equivalent).
If all step already done, then you can test to update your bootloader, refer here:
https://www.raspberrypi.org/downloads/
https://my.cytron.io/tutorial/raspberry-pi-imager-updating-bootloader
Internal use:
https://www.raspberrypi.org/forums/viewtopic.php?p=437084