Georges Holland

Hey, I think I'm impacted by the same issue. I've replaced the original fan of the HC4 with a Noctua NF-A4x10 5V PWM earlier this year. It was working as expected, but since couple weeks the fan is at 100% speed continuously, which is loud. It sounds like it's a software upgrade that broke the PWM control, but no idea which one. I've done part of the same testing you mentioned but didn't managed to find a fix neither. I'm probably even more beginner than you, so I don't think I can help much unfortunately. How can we get more eyes on this issue? Did you post on Odroid Forum?