PWM Fan Not Working

Last week I noticed the PWM fan isn’t turn on anymore on my Monoprice Select i3 Plus model # 15711. I’ve tested the fan and it works when I hook it up to the extruder fan port on the interface board. How do I determine if there is an issue with either the interface board or the main board?

It does not mean that the fan is OK because you are testing it without PWM. Those fans are unreliable so it is probably the culprit.

If it is not, you need to make some measurements with a multimeter. Start with the connector of the fan. Depending of your multimeter, it will show you the frequency or maybe even duty cycle. Otherwise, you can just confirm the voltages at 0, 50 and 100%. You can also make a continuity check on the interface board.

And if it gives nothing, it is the mainboard.

Note: As it is not related to ADVi3++, I move it to the appropriate category. Please post in the right category next time.

When the fan is on, I get no power to the connector when using a multimeter. I checked continuity for the connector. There was no continuity. I have continuity between the connector and the ribbon cable. So I think the interface board is working. It looks like the issue is with the mainboard. Is there way to check the mainboard or do I need to get a new mainboard?

I have never traced the fan pin on the mainboard to see if there is any circuitry but I assume there is a MOSFET somewhere in the path.

The pin on the microcontroller is PE3. Maybe you can try to see if there is any signal here.