I can't control the fan speed and the fan still spins after shutdown

[bladetins]

Question 1: I use a 4-wire pwm fan for jetson nano, but it always runs at full speed and can’t adjust the speed. regardless of use

sudo sh -c 'echo 0 > /sys/devices/pwm-fan/target_pwm'

Or directly use vim to modify the value of the corresponding file, it cannot stop or slow down.

Question 2: I use the DC port to power the jetson nano. After the power is turned off, the fan port still has power, and the usb port is also powered. How to make these ports also powered off?

(Jetpack 4.6) (L4T 32.6.1)

Thank you, looking forward to your reply.

[JerryChang]

hello bladetins,

had you execute jetson_clocks with the --fan options? this will set maximum PWM fan speed.
could you please also check /sys/devices/pwm-fan/cur_pwm for the PWM settings.

[bladetins]

I didn’t use the

jetson_clocks --fan 

But I saw other tutorials that use

sudo /usr/bin/jetson_clocks

, which I also used.

I use the cat command to open /sys/devices/pwm-fan/cur_pwm, the value inside is always 0, no matter if the fan is plugged in (full speed operation) or unplugged

[JerryChang]

hello bladetins,

please access Jetson Nano Product Design Guide, and check [Figure 11-6. Jetson Nano Fan Connections] for reference, thanks

[bladetins]

Thank you!