Fan on board not working.

Hello Admin.

     Last month i buy jetson tx2.Now i try to install software but i found fan on board not working but ubuntu can started.

Why fan not working or i mistake for installation.


fan will start on you execute ./ for example or on overheating, perhaps.

FYI, fans only need to run when heat goes up…unless the Jetson is under load it doesn’t use enough power for the fan to matter.

Thank you all.I try to execute ./ it work.And What command for stop fan?

Before launching script for boosting, you can store your clocks config into file /home/ubuntu/l4t_dfs.conf and later restore with :

sudo /home/ubuntu/ --store       # save clocks config into l4t_dfs.conf file
sudo /home/ubuntu/               # boost clocks
sudo /home/ubuntu/ --restore     # restore clocks config from l4t_dfs.conf file

Back to slow clocks, after a while when heat will have decreased enough, the fan will stop.

@Honey_Patouceul thank you very much.

Hi everyone~ I confused about the fan.
If I don’t execute ./ the fan seems not working.
I have searched some discussion and find out someone say using adapter will cause the fan not working.
However,I changed to use HDMI monitor and it also not working unless I execute ./

If you are on a different board than Jetson devkit, it may be different.

On the Jetson devkit board, it is normal that the fan doesn’t start when the Jeston TX boots.
This doesn’t produce so much heat and normal convection is enough, no need to waste power for activating a useless fan.
When you run intensive tasks on CPUs and GPU, if it gets too hot, then fan should start. When it is cold enough later, it would stop.

When running, it forces the fan to run at full speed, because it is likely to be hot soon.

If you don’t care about power saving and just want to have the fan always on, you may start it in startup script such as rc.local. This requires root priviledge:

echo 255 > /sys/kernel/debug/tegra_fan/target_pwm

Thanks for your reply. I just afraid it won’t work when it gets too hot.
Let me make sure I have it right.
The fan will works whether I connect the monitor with HDMI-VGA adapter or complete HDMI.

this the discussion I mentioned in last talk:

The red light is just a power indicator…not a fault, it is the reverse…“a good thing”. Not all earlier carrier boards had all of the indicator lights.

The fan should be independent of whether video is connector or not. On a dev board the fan won’t run unless generating enough heat to require it…remember that at idle this only draws 7.5 watts…you have to actually try to do something to bring up heat. Non-dev carrier boards may differ.

NOTE: Having video connected and working might imply using the GPU and bringing up heat some…this is the only reason it might change whether the fan runs or not.

FYI, an HDMI-to-VGA adapter will break video auto-configuration. If you use this you must get lucky for video to work.

Thanks a lot. You solve all my doubts.