I just got a raspberry pi in the mail from element 14. Its a model B. I also bought this SD Card to boot from. When I first put in my SD Card and plugged in my power the PWR led turned bright red, then the green ACT light flickered. Then after a few seconds the PWR led would remain constantly red while all of the other leds would remain dark. After several attempts I believed that my SD Card was defective. So I did this. When that finished I put the SD card in the SD slot and then plugged in my power. Nothing changed. What am I doing wrong?

  • 1
    Make sure that the write-protect switch on the card is fully in the read-write position (i.e. make sure it's fully unlocked)
    – recantha
    Apr 6, 2013 at 6:23
  • @recantha is that when the switch is up (toward the connectors) or down (away from the connectors)?
    – Coder404
    Apr 6, 2013 at 10:10
  • On my card, the little switch gets pushed towards the connectors
    – recantha
    Apr 6, 2013 at 14:36
  • 1
    Any display output?
    – ergosys
    Apr 6, 2013 at 18:06
  • You have not actually described what's wrong. My LEDs flicker for a bit when it boots too, then just the red PWR stays on after that, so I presume this is normal.
    – goldilocks
    Apr 6, 2013 at 18:28

1 Answer 1


Often times this sort of behaviour is a result of two common problems: an invalid SD card, or incapable power supply. What is the peak current rating on the power supply you're using with your Pi? The general rule of thumb is to use a power supply that can handle at least 1A of current.

  • my power source's output is 5.0V and 1000mA
    – Coder404
    Apr 6, 2013 at 2:32
  • hmmm bummer. Perhaps try performing a check sum on the SD card and compare it to the ones listed on the RPi foundation website.
    – Alexander
    Apr 6, 2013 at 2:52
  • How Could I do that on a mac?
    – Coder404
    Apr 6, 2013 at 2:55
  • My issue was an invalid SD Card. I had to reformat it. Thanks for the help!
    – Coder404
    Apr 16, 2013 at 23:09
  • Sorry I didn't reply to your earlier comment about instruction on doing a checksum, the notification must have been drowned out or something.
    – Alexander
    Apr 17, 2013 at 1:53

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