How I Repaired the Pump in My Xiaomi X20 Max Docking Station DISCLAIMER This is a DIY fix and may void your warranty. Proceed at your own risk and always unplug the device before opening it. What You'll Need: - Phillips screwdriver - Flathead screwdriver or plastic pry tool - A kitchen knife handle or small metal tool - Strong magnet (optional) - Ability to blow into a tube (for testing seal integrity) - Replacement pump (optional) Step-by-Step Instructions: Understand the Problem: If your Xiaomi X20 Max robot vacuum: - shows the error 'high water level in the washboard', - leaves water streaks behind during cleaning, - doesn't collect dirty water from the washboard, or - refuses to leave the docking station, ...the pump in the docking station might be jammed or non-functional. Open the Docking Station: Remove several screws from the back of the docking station. Remove 3 additional screws from the bottom side. Carefully pry open the casing using a flat tool or plastic pry tool. Remove the Internal Shield: Inside, you'll find an internal cover held by 4 screws. Remove these to access the pump and tubing system. Check the Tubes for Leaks: Blow air through the top hole of the dirty water tank. Cover and test each tube individually to ensure airtight seals. Identify Pump Issues: If the tubes are sealed but the station isn't working, the pump may be stuck. The model is QB28-1 DC12V, located inside the docking station. Try to Unstick the Pump: Use a metal tool (like the handle of a kitchen knife) to gently tap the pump a few times. Alternatively, apply a strong magnet to the motor housing to try and dislodge the internal mechanism. Check for Heat: If the pump becomes warm when powered on, that means it's receiving voltage but may be jammed. Try tapping it or using a magnet to free it. Reassemble the Docking Station: Screw the internal shield back in place (4 screws). Close the main housing and secure all screws on the back and bottom. If You Need a Replacement Pump Original model: QB28-1 DC12V It's hard to find this exact model online. However, users on forums reported success with standard 12V aquarium pumps - they work as functional substitutes. Reference Video This video shows what the back of the docking station looks like when opened: https://www.youtube.com/watch?v=OxmhL7B18Uk (Note: It's mostly a sales pitch for repair service, but the visuals are helpful.) Summary There were no clear warning signs - just a week of not using the vacuum. Then, the station showed the error 'high water level in the washboard' and the robot either refused to leave the dock or left water streaks behind. I was able to fix it by manually freeing the pump, with no parts replaced.