Installation does not start

I am just trying to get into the subject as beginners hence my question.
I followed the instructions to install on a Raspberry Pi (flash SD card etc.) Then I plug the SD card into the Raspberry Pi and now the installation should start. But nothing happens. Neither on the screen that is connected something happens nor, is the web page to set up accessible. Am I doing something wrong? Thanks

Did you buy a recommended power cable or use a random one you had around? Power cable issues are a common one.

Otherwise not sure, should definitely be something on the connected screen. Maybe try flashing Raspbian and getting that started up as a test to see if everything is functional. Then reflash HAOS and try that once you’ve confirmed the basics are all working (I’m assuming you’re trying to flash HAOS and not debian, you didn’t say so I’m guessing).

Thanks for the answer.
I use the original power cable. But I will order a new one, maybe it is broken. Have otherwise done everything according to the instructions. You can do almost nothing wrong. Can I somehow test whether the Raspberry pi is broken? The lamps on the LAN port and the screen remain dark. Only one red lamp lights up on the Pi.

If only the red led lights then it is not reading the ad card. A green Lee’s should flash as it reads the card. Try flashing the card again or using another card.

With a new SD card it worked. Thanks for the support.