it's your screen which is odd! Backpowering is the problem. If there is fan supply voltage (in case of your Pi 5V from USB) but no PWM control (as the Pi is off and 3.3V rail is down) any 4pin fan will run at full speed.I'm getting the same issue. Fan is clearly getting power back fed from USB (USB is connected to a 12v touchscreen).
For now I'm going to connect screen and pi to same power supply so it turns both of, but it is odd behaviour!
Use devices which are according to USB spec and you don't see such problem.
Statistics: Posted by aBUGSworstnightmare — Sat Apr 20, 2024 4:26 am
