The kit contains Raspberry Pi 4 Model B with 2GB with the original power supply. The problem is that the (green) Act LED lights up 4 times (3 short 1 long) with Raspberry Pi OS sd-card inserted.
Until recently, my Raspberry worked very well. I started using it successfully for "Home assistant", headless (without hdmi connection with an monitor). It worked flawlessly with "Home assistant" for about 3 months. Without doing anything to it, in one morning it stopped working. I restarted it and it didn't work anymore. I have tried various other operating systems for raspberry. I also changed the sd card. The card was rewritten with Raspberry Pi imager.
I searched in the LED warning flash codes section but i did not find this sequence (3 short 1 long).
Thank you in advance for your reply and for taking the time to read the message.
For example : The video is not made by me, but it explains my problem very well.
The Raspberry Pi 4 works differently than previous versions which means the blink patterns are also different and indicate different things. The boot up is more complex and has more features, so if it doesn’t find a valid start.elf file on the SD card it will blink the LED four times with an interval between the four blinks. Which means unlike the older boards it won’t mean that the SD card is booting, it means the code can’t find the SD Card at all.
The YouTube looks like four blinks of equal length to me.
