OK, I have plugged in another pwm fan, and /sys/devices/platform/cooling_fan/ is found again. I rebooted my pi 5 five times, and the directory is there every time. The presence of this directory suggests that the fan is under pwm control. I think the conclusion is that the pwm fan of my active cooler somehow deteriorated and caused the pi not able to find it.
I plugged the deteriorated fan back in and the issue was reproduced.
I think I am just going to write some code to control the fan without relying on pwm.
Thanks for the suggestion to investigate the connection. (It turned out the root cause of the failure was the fan, not the connection nor the pi.)
I plugged the deteriorated fan back in and the issue was reproduced.
I think I am just going to write some code to control the fan without relying on pwm.
Thanks for the suggestion to investigate the connection. (It turned out the root cause of the failure was the fan, not the connection nor the pi.)
Statistics: Posted by manworld — Sat Jun 29, 2024 11:59 pm