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

Question

I just received a Raspberry-Pi -3-B. The kit from "LoveRPI" (apparently, via Amazon.com) contained a Pi from "Element-14" and a no-name power-supply. I installed the latest "Raspian w/ Jessi" on a "SanDisk MicroSDHC UHS-I Class-10 16GB card", and discovered that the included power-supply was DOA (looked online, others have complained, a lot, about these Power-supplies). However, I have several other Pi models and switched to another 2.5A Micro-USB power-supply that I have. The Pi boots and everything seems to work, fine (blazingly-fast), networking, software, etc... However, when the Pi is doing nothing (with no software actively running, zero CPU-usage) the SD-Card-access-light (green LED) blinks continuously (about once a second). The Red-LED is steady. I have not noticed this on my other Raspberry-Pi's. Is this normal? Is this caused by my SD-Card? Is my Pi damaged (possibly by the original power-supply)?

Also... a silly question... my "Element14 Raspberry-Pi" (inside the "element14" box) came in a paper/cardboard envelope, instead of a regular anti-static bag. The envelope does have the "Element14" logo, so is this all OK? I'm a little nervous after the power-supply problem. Thanks.

spannerspencer · Answer

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?

balearicdynamics · Answer

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

Former Member · Answer

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

condocolin · Answer

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.