Not sure what I've broken - NF-A4x20 5V PWM on FAN0
OK, I've had this working fine previously with not problems, but after moving the duet wifi board into an new enclosure I cannot get the cooling fan to work.
The fan itself is a NF-A4x20 5V PWM.
I've connected the 5V to expansion pin 1.
GND to expansion pin 2.
PWM control to FAN0-.
I have not connected the speed sensor.
i've set up the fan on config.g with:
M106 P0 S0 I1 F25000 H-1
The fan will not spin at all, no matter what % speed I set it to.
I've checked continuity of all cables and they are all fine.
5V (ex P1) reads as 4.66V against GND (ex P2).
If I connect a 12V blower style pwm fan (across VFAN0- and V_FAN (12V)) it runs as expected at M106 P0 S0 F500 I0 H-1
The killer seems to be that if I just connect the Noctua fan to an Arduino and control it from there it seems to work fine.
Any insight would be fantastic.
Does the 5V fan run at full speed if you leave the PWM wire unconnected?
No. This is the same behavior on the arduino.
PWM fans normally run at full speed with the PWM control wire not connected. Perhaps yours has developed a fault. Adding a pullup resistor (try 1K) between the PWM wire and +5V may get it working again.
This is working. Thank you. Only issue is that it will still run while the ATX power is off, but this will do until i have a replacement for it.