The red led repeatedly blinks 4 long 4 short and the Pi doesn't boot. Tested with various power adapters.

When powered up without an SD card the red led is solid. I'm using an SD card that works fine with an RPi 2 and 3B.

What could be the problem?

  • 1
    This is a bit light on detail. It would be nice to know if the Pi boots and such like.
    – joan
    Aug 29, 2018 at 14:55
  • @joan updated. Any other details?
    – Sparkler
    Aug 29, 2018 at 14:57
  • check if tinycore supports the 3B+ - last I read, it did not Aug 30, 2018 at 6:38
  • Hi, It indicates the power issue on your board. Can you explain the power supply details? Pi needs constant 5V, 2.5A. If there is no load, It can work with less current source but I can't compromise with the voltage. If it drops(Obviously with some tolerance), Red LED starts blinking. Mar 11, 2020 at 7:06
  • I would be tempted to flash Raspbian OS Lite to a USB drive and see if it boots from that if you have one that can boot a Pi. Some USB adapters will only boot the OS if you have bootcode.bin on the SD - not what you want if its the SD card gone pop...
    – user115418
    Jul 9, 2020 at 1:05

2 Answers 2


According to this a blinking red LED indicates power problems but does not specify any pattern to the blinking.

If it were the green LED flashing then further down on the same article has some more suggestions that fit better with your description of four flashes cycling.


RED LED is controlled by "STATUS_LED_R" signal. Only solid knowledge available to public is that RED LED is a power indicator and turns off when RPi supply voltage goes bellow 5V with some tolerance. Even with "reduced schematic" it really does not matter from where this STATUS signal comes from, what is important is its absence indicating power problem with your SD CONNECTOR, long time known "problem" - they do go bad! If your SD works elsewhere , and your RPi stays on without it - what else is there which is common? Try different SD to verify my guess.

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