There are a lot of issues around here about corrupted cards and RPi not booting. But can somebody explain to me what is the problem with RPi and some card(I mean technical explanation)

Why do some cards work and other not?

I.e. I'm able to format the card, write an image. I can do everything with my laptop and the SD card. But what problem does RPi have with this card? Both leds are on(green, red) no blinking, I guess it is saying not able to read the card. I'm really interested why normal card should not work with RPi.

  • That's indeed a good question. I've tried once to make multiple boot cards, using the same image and methods to create some Raspbian cards. But one of them simply did not work when the other cards did. The "faulty" one was from a different brand, dunno if it's related.
    – Mauker
    Commented May 26, 2015 at 15:27
  • 1
    That is exactly it, maybe they are not broken, just need other treatment or something, but without knowing what should be wrong with the card one cannot fix them.
    – Zveratko
    Commented May 26, 2015 at 16:55
  • See also elinux/RPi troubleshooting: "there is a difference between the quad core Pi 2 (BCM2836) and the other models if there is no SD card inserted, or the SD card is improperly formatted. The former will have both red and green lights on bright and steady. The latter will have only the red light on. This indicates the Raspberry Pi cannot find a valid image on the SD card." (i.e., it is the same as if there were no card at all).
    – goldilocks
    Commented Apr 5, 2017 at 12:04

1 Answer 1


The SD card must be formatted with a set of instructions that the processor can understand. The operating system is all stored on the card.

If you get the LED's behaving like that just when the raspberry pi is plugged in, then it means that the operating system on the card can't be read by the processor. To get a proper image, go to the raspberry pi downloads site for disk images.

  • I guess it is more connected with the SD card itself. The same image was working fine with some other card, but not with this one. Tried already multiple images. Thing is if there is way how can I on laptop verify if the card is valid. I'm writing the image the same way I used fot the one before and it is not working. There is list of supported SD cards, the question was why we need such list, what exactly is wrong with the other card that won't work? Is it hardware are they not conform with some kind of SD specification or what?
    – Zveratko
    Commented May 25, 2015 at 7:57
  • Look here.
    – Will
    Commented May 25, 2015 at 8:04
  • 1
    You can run the card in a laptop with qemu - this establishes that it is correctly written, but not that it will definitely work in a Pi! Commented May 25, 2015 at 8:41
  • For me it looks like, it is pure magic if the card will work or not.
    – Zveratko
    Commented May 25, 2015 at 10:56

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.