i pulled out the the fuse and put it back again and now it is working? 😄 WTF so much frustration without any reason 😄

Mosfet usually fail always on (or catastrophically to the point where there is nothing left of the part)

So if the fan works on the always on output but not on Fan0 before and after the replacement its not untinkable the fault is elsewhere, unfortunately the next part in the chain is the main processor (FAN0 goes straight to pin 90 on the ATSAM4S8C)

To further diagnose verify the part has connectivity from the Gate to R42, from the Drain to Fan0- on the header and from Source to ground. Then (with power on) check if you have a gate signal on either side of R42 with respect to ground when the fan is turned on.

7e51baf8-718b-4112-bf12-47cc46fc8f10-image.png

@droftarts Thanks. Just checked. It's the blown fuse.

I would be interested to find out what component needs swapped out. I have some experience soldering, but not sure if it's worth attempting to fix without knowing more first.

Like I said I was able to get everything working on Fan2 so not a huge concern for me currently.

So I measured the voltage again. I plugged a connector with 2 cables at the fan1 pins and connected this to a multimeter.

If I measure between VFAN and FAN1- I see 7.6V when the fan is at 0% on the web control and 12V when the fan is at 100%.