New Raspberry-Pi 3, Green-LED keeps blinking.

Here is the latest. I discovered that the power-supply is actually a 2.0A (I have used it for some time on a Raspberry-Pi 2), and I have also tried another, new, 2.0A micro-usb power-supply, that I have. I have run the Raspberry-Pi-3 for several hours without any apparent issues. The only symptom (an, approximately, 1/3-second flash of the ACT-LED, about every second) continues whenever I am not actively interacting with the Pi. Otherwise, I would not even suspect anything was wrong at all. Does anyone know how to determine whether the flashing LED indicates actual SD-card access (OS logging, or some other internal OS operations, maybe?), or whether it is some kind of error-condition?

As I stated earlier, this is a brand-new Raspberry-Pi 3B (my first Pi-3), with a fresh install of pure (not "noobs") "Raspbian-Jessie PIXEL". And, none of my other Pi's exhibit this type of continual LED/SD-card access-flashing (including my other "Raspbian-Jessie PIXEL" installations, on my Pi-2). So, is this just normal SD-card access, or is this unusual? How can I monitor actual SD-card RWs? I am suspecting, based upon the otherwise seemingly normal operation, that there is some actual storage-device operation going-on in the background. Can I (and should I) disable this repetitive storage device access? As I said, it just doesn't seem right that a Raspberry-Pi LED should continually be flashing (unlike the other Raspbian installations that I have). Perhaps, I should re-format the SD-card, and re-install "Raspbian-Jessie".

Hi there Raife! Glad you figured out the PSU issue (did you get a replacement?). A 2.5A power supply is recommended for the Pi3, although it should still run (maybe without any power-hungry USB peripherals attached) on your 2A PSU. You might just see the lightning symbol pop up from time to time, to let you know it's a bit power starved.

To my knowledge, you're right about the ACT LED. It's flashing to let you know the Pi is accessing its OS. I doubt it's a problem though -- it's probably just performing a regular function, like checking the Wi-Fi or similar.

Just in case, I'll move this conversation over to our Raspberry Pi section so someone who knows a little more than me might be able to offer some advice.

Any plans on what you're going to do with your new Pi?

Hello Raife,

AFAIK there is no direct relation between the led and the SD card access (I suppose to avoid any slowdown in the SD card reading).

Anway, I suggest to read the very useful information specifically relate to the Raspberry PI Linux and hardware behaviour on the e-linux.org site. The behaviour of the green led is shown below, but I have not yet tested if this is coherent with the last hardware versions of the board (model 3B)

the green light will blink in a specific pattern to indicate some types of errors:

• 3 flashes: loader.bin not found
• 4 flashes: loader.bin not launched
• 5 flashes: start.elf not found
• 6 flashes: start.elf not launched
• 7 flashes: kernel.img not found

Firmware since 20th October 2012 no longer requires loader.bin, and the flashes mean:

• 3 flashes: start.elf not found
• 4 flashes: start.elf not launched
• 7 flashes: kernel.img not found
• 8 flashes: SDRAM not recognised. You need newer bootcode.bin/start.elf firmware.

If start.elf won't launch, it may be corrupt.

Note that 4-flashes may point to a defective SD-card holder, if one or more of the data contacts is intermittent it can lead to this problem.

Enrico

Thanks for all the help. This is so cool.

Here is the latest, latest...

I went ahead and re-formatted the SD-Card (SD-FORMATTER under Windows). And, re-installed the Raspbian-Jessie-PIXEL ".IMG". As I said, after determining that the original power-supply that came with the Raspberry-pi, was non-functional... dead... dead... dead... I switched to other (actually 2.0A) power supplies, and everything has run without problems. The Pi boots normally, the OS runs normally, I have complete wireless-networking, and I have added new software and files (Updates, VLC, Arduino-programming, wall-papers, music, Etc.), and I have SSH'ed into the device from my Android-tablet and controlled the Pi remotely (which I still find to be totally cool... despite years of computers, Windows, Linux, networking, and electronics... Yes, I am a really nerdy).

Further, my Raspberry Pi's (Zero's, One, Two, and now, Three) all use the same keyboard, mouse, and wireless adapter, via a powered-USB hub (I plug the hub into the Pi which I am using at the time. This also means I actually have two wireless-LAN-adapters, and the wired-adapter, available when I am using my Pi-3).

The only thing that has confused me, was the fact that, despite operating normally, the "ACT" LED just kept blinking continuously (about once a second) whenever The Pi was (presumably) sitting idle. I turned-off Bluetooth (no devices for the Pi... yet), but while powered-up, the "ACT" LED just kept blinking... non-stop. However, after a few days of playing with my Pi-3, the "ACT" LED seems to have finally settled down, and only blinks occasionally (as I thought it should), or when I am actively using the OS. It was just a mystery, and my inner geek worries about anything, technological, that I can't properly explain. So, I am still poking into this.

Thanks again for the help.

Hello,

I had the same circumstance, and I still haven't been able to remotely access mine yet, but I noticed the green LED stops flashing this way after a USB keyboard is inserted. So maybe it is scanning the ports, or just signalling "no peripherals"?

Cheers, Colin.

Its possible to change the trigger for the led to the following scenarios:

none kbd-scrollock kbd-numlock kbd-capslock kbd-kanalock kbd-shiftlock kbd-altgrlock kbd-ctrllock kbd-altlock kbd-shiftllock kbd-shiftrlock kbd-ctrlllock kbd-ctrlrlock mmc0 mmc1 timer oneshot heartbeat backlight gpio cpu0 cpu1 cpu2 cpu3 default-on input rfkill0 rfkill1

so:

echo none > /sys/class/leds/led0/trigger

will turn off the led completely (if it becomes annoying)

echo heartbeat > /sys/class/leds/led0/trigger

will cause the led to flash with the linux heartbeat pattern

echo timer > /sys/class/leds/led0/trigger

will cause the led to flash once a second

just echo the desired trigger event from the list above

Hi Lucie,

That is real interesting! Have to jot that down for 'Ron! Might be handy for specific projects.

Cheers, Colin.