Yes, that's the first thing to try.so should I try using 24v dc VDD (+) and ground (-) and PWM input left open?
It could also be the motor needs PWM control signal to operate.If nothing works, the motor is most likely dead.
What you know (or care about) is not relevant. The OP may have different experiences to you.Battery & PCB are in fan enclosure so no chance of reverse battery during normal use.
Yes, the MCU would know if battery Volt is low & could stop the fan via T2.
In a test last year I discharged all the way to stop & observed the fan speed slowly decreasing in steps getting towards LVC. I don't know (or care) if LVC was the battery BMS or MCU turning off T2.
I'm just meaning when I did the test, as long as something was doing Low Volt Cutout I didn't care.What you know (or care about) is not relevant. The OP may have different experiences to you.
Your schematic makes sense now that I realise that T1 is a switch mode regulator for battery charging. I think the most likely explanation for D1 failing would be the battery connector being reversed at some point. (Assuming it is possible to insert the connector the wrong way round.) It would be interesting to know if there is any voltage on the VDD pin of the motor connector when the TS answers the question in post #46. If the battery voltage was too low it is possible that the MCU will not enable T2 to protect the battery from over discharge.
A question to the TS. Measure the voltages with respect to GND at the source and drain connections of T1 and T2 and the voltage on the gate connection of T2. (This is with the controls of the device in the state that would normally cause the ban to run.)
Yes! my multimeter have Diode Test function. I have re-solderd battery pins.It could also be the motor needs PWM control signal to operate.
Be careful, if inadvertently apply +V supply to PWM wire this could damage the control circuit in the motor.
When you finished playing with the motor...
Does your multimeter have Diode Test function? (most do nowdays), when you check the components I suggested we will know more what might be ok or need to replace.
The diode test applies a small current & displays the voltage of the circuit under test. It is great for revealing shorts, can see briefly ..uF capacitor charging, AB compare test etc...
The battery would have supplied most of the current to finish off D1 so T1 could be still ok.
D1 is not needed to run fan from battery, its part of the charge circuit, DON'T connect DC charger supply without D1 diode!, T1 is only a 30V device.
Have you checked/re-solder battery +pin solder join ? It looked like cracked solder in the photo.
As you mentioned earlier you have LED's so this shows logic supply N1 & MCU N2 are ok.
OK, could be something failed in the motor then.No! Not working