F4
Xiaomi
Brush Motor Driver / Accessory Power Fault
Display shows F4, vacuum cannot detect or drive the motorized floor head
Advertisements
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Advertisements
Possible Causes
Failed MOSFET driver on main PCB, Shorted brush motor, Damaged accessory power pins, Overheated driver circuit
How to Fix / Troubleshooting
Safety first: Remove the battery and detach all accessories before inspection.
- Test main unit alone: Run the vacuum without any powered accessories. If the main motor runs normally, the issue is isolated to the accessory power circuit.
- Inspect accessory pins: Check the power pins on the main body and wand for signs of burning or discoloration. Do not use the vacuum if pins are melted.
- Try different powered head: If available, connect another Xiaomi motorized head. If F4 only appears with one head, replace that head.
- If all heads fail: The brush motor driver on the main PCB is likely damaged. The main body PCB should be replaced; board-level repair is not recommended for most users.
Advertisements
Repair Difficulty
Professional Required
5/5
Required Part
Main Control PCB
Check Price on Amazon
We may earn a commission from links on this page.
Advertisements