Not booting. Tried different SD Cards and Images

Hi My Banana Pi M4 never booted. Tried various official images, different SD cards. I bought the power adapter from the seller on aliexpress to make sure that it will work. Still, tried other power supplies, too. No change. Boot switch is on 0 position. After I connect power, no LEDs light up. I press the power button for a few seconds, sometimes the red and green LED come on and stay on. Nothing else happens. Sometimes, the red and green LEDs turn on and then off within a second or so. I bought a TTL - UART cable and connected it to the console. Again, the behavior varies. Sometimes I got goto fsbl: 0x8008000 and then nothing happened. Sometimes I get some hardware info as well, but nothing else. Should I try reinstalling the EEPROM? Where would I find that image? Are there instructions anywhere on how to do this?