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Not a duplicate of this RPi.SE question, as I'll explain in a moment. GPIO.RPI_REVISION returns 3.

As far as I can tell, looking at my B+, there are no LEDs labeled: OK, FDX, LNK or 10M. There are two embedded in the Ethernet port, and two on the opposite side of the board. The ones on the Ethernet are unlabeled, but I can guess what they mean. The other two are labeled ACT and PWR.

PWR only turns on once in a great while. My RPi is running just fine, and the PWR diode is unlit (which others say should never happen). This is the one that confises me the most.

AMP seems to turn on under I/O heavy load. (Seems to be the equivalent of the old OK LED).

What do these lights signify?

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PythonNut
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1 Answers1

70

I believe the following is correct for the B+.

Red PWR LED

  • on if power OK
  • flashes (or goes out) if the power drops below about 4.63V

Green ACT LED

  • steady on if no SD card during boot

  • irregular flashes for SD card access

Ethernet Socket Left LED (yellow)

  • on 100-Mbps connection

  • off 10-Mbps connection

Ethernet Socket Right LED (green)

  • on if link established

  • flashes for port activity

  • off if no link is established

http://www.raspberrypi.org/forums/viewtopic.php?p=577688#p577688

http://www.raspberrypi.org/forums/viewtopic.php?p=646072#p646072

http://ww1.microchip.com/downloads/en/DeviceDoc/9514.pdf

joan
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