Raspberry Pi Status LEDs Explained

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All Raspberry Pi boards have at least one status LED. The number and position of these varies between the different models. Below is a list of the different configurations you are likely to find on your Raspberry Pis.

Pi 3

Pi 3 Status LEDs
The Pi 3 has two LEDs on the PCB where one is labelled “ACT”.

Pi 2, B+, A+

Pi 2 Status LEDs
The Pi 2, B+ and A+ have two LEDs on the PCB. The Pi 2 and B+ also have two on the Ethernet socket. The PCB LEDs are labelled “ACT” and “PWR”.

Pi Zero

Pi Zero Status LEDs
The Pi Zero only has a single activity status LED. There is no power LED.

Model B (rev 2)

Model B (rev 2) Status LEDs
The Model B (rev 2) has five LEDs labelled “ACT”, “PWR”, “FDX”, “LNK” and “100”.

Model A

Model A Status LEDs
The Model A has two LEDs which are labelled “ACT” and “PWR”. The PCB includes labels for the three network status LEDs but these are not populated.

Model B (rev 1)

Model B Status LEDs
The Model B has five status LEDs labelled “OK”, “PWR”, “FDX”, “LNK” and “10M”.

The LEDs have the following meanings :

OK/ACT Green SD card activity
PWR Red Power
FDX Green Full Duplex (LAN) connected
LNK Green Link/Activity (LAN)
10M/100 Yellow 100Mbit (LAN) connected

You’ll notice that the “OK” and “10M” labels changed with the Model B revision 2 PCB.

Ethernet Socket LEDs

Ethernet Status LEDs
The Pi 3, Pi 2 and B+ all have an Ethernet socket with two additional status LEDs.

10M/100 Yellow 100Mbit (LAN) connected
LNK Green Link/Activity (LAN)

Power Status

The red power LEDs indicate that the Pi has an active power supply. In the Model A and Model B (rev 1) the LED is connected directly to the 3.3V supply. If it fails to light or flashes it indicates that there is a problem with the power supply.

In the later models (A+, B+, Pi 2 & Pi 3) the power LED is slightly more intelligent. it is connected to the 5V and will flash if the voltage drops below 4.63V.

Troubleshooting

There is more information on troubleshooting using the status LEDs over on the eLinux Wiki R-Pi Troubleshooting page.

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5 Comments

    • Yes. “10M” was simply a mistake and always should have been “100”. They had to wait until they tweaked the board for other reasons before it was worth correcting.

  1. Raspberry PI 3 Model B has 2 LEDs on the board one red one green and two on the wired ethernet connection, one yellow and one green.

    They don’t seem to be clearly labelled, but the green one on the board might be something to do with SDcard access. The red one looks like it might be power but not sure what it means when it starts flashing.

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