Aside from physical methods of disabling the LED, like the black-paint suggestion, and cutting a PC trace, there is obviously a software solution, as the LED state is clearly manipulated by the BIOS and OS's. Under Debian Stretch, here's a clue: Code: /root (2) # dmesg |grep " led" [ 3.274709] ledtrig-cpu: registered to indicate activity on CPUs [ 4.540693] ahci 0000:00:13.0: flags: 64bit ncq led clo only pio slum part deso sadm sds apst Code: /root (2) # find / -name ledtrig-cpu 2>/dev/null [nothing found] /root (2) # find / -name ahci >/dev/null /sys/bus/pci/drivers/ahci /sys/module/ahci /sys/module/libata/holders/ahci /sys/module/libahci/holders/ahci And there also these files that contain the string "LNXPWRBN": Code: ./devices/LNXSYSTM:00/LNXPWRBN:00/input/input5/capabilities/led -r--r--r-- 1 root root 4096 Jul 2 09:47 ./devices/LNXSYSTM:00/LNXPWRBN:00/input/input5/capabilities/led ./devices/LNXSYSTM:00/LNXPWRBN:00/input/input5/capabilities/led: ASCII text /proc/bus/input/devices:P: Phys=LNXPWRBN/button/input0 /proc/bus/input/devices:S: Sysfs=/devices/LNXSYSTM:00/LNXPWRBN:00/input/input5 Also, the X86 schematic diagram shows LED D25 on page 18 at location ~C1 apparently controlled by line ATPSCK/IO2 shown in four places also on page 18 apparently controlled by Intel Curie chip U51F possibly on the SPI bus. So, perhaps there's a way to access the power LED via that bus. The Intel Curie data-sheet mentions the ATP_SPI_S_MISO port in four places as an output port for PWM or data. I don't pretend to understand all this. But, hopefully there is enough information here to enable someone more knowledgeable than I about this topic to further elucidate software controlling the Udoo X86 power LED. Now that I've researched the above information, I believe it is LED D34 (not LED D25 which is doubtless the IR transmitter LED) that is actually the green/yellow power LED shown on page 22 of the schematic at location C2. The green LED is apparently controlled by Q23B, DMN63D8LDW -7, and the signal is apparently brought out to pin 16 of connector CN13 shown at location B4 on page 18 of the schematic. There may be another clue in this message.
Very nice, thx for the information, currently i'm running Windows 10, i'll look more into this when i've installed linux.
LED D25 is for Arduino 101's IO #13. Arduino 101's program control it (say blinking.) The other Green/Orange LED pair is simply used to indicate the system status. (It is tagged onto the essential system power control signal/status called Platform_Reset. One cannot and should not modify the system control/status signal sorely for the purpose of not showing such signal status.) ccs_hello
