!!
critical Msi

Error Code BOOT

Boot device is not detected or has failed. Indicated by EZ Debug LED.

? What Causes This

Storage device not properly connected, no bootable OS installed, or storage device failure.

How to Fix It

  1. Power off and unplug the system.
  2. Check all SATA and M.2 connections are secure.
  3. Ensure boot drive contains a valid OS installation.
  4. Check boot order in BIOS (press Delete during POST).
  5. Try different storage device if available.

Source: page 42 of the official manual

From the manual

Manual page 42 — Msi error BOOT

This error code appears in:

Msi B550-A Pro Motherboard