The LED flashed 7 times, and repeated that.
LED warning flash codes
Seven flashes is one of "Kernel image not found", "Secure-boot configuration is not valid", or "RP1 not found". Given your description it's most likely the first one so a problem with the SD card or with what has been written to it.
Or with any changes you have made to your config.txt relating to which kernel should be used.
Statistics: Posted by thagrol — Thu Dec 11, 2025 9:37 pm