Add-on: Bambu Lab A1 Series Maintenance Bundle

1Safe Unloading and Power Off

•  [Important] Always turn off the printer and unplug the power cord before performing any operations.
•  Unload the filament from the printer (if the power is off, you can manually cut the filament and pull it out).

2Remove Toolhead Rear Cover and USB-C Cable

•  Hold the bottom of the toolhead rear cover, carefully pry it open and remove it.

•  Use an Allen wrench to remove the 4 screws securing the USB-C cable, then pull the cable upwards.

3Remove Extruder Mainboard Screws and Disconnect Cables

•  Remove the 3 black screws securing the extruder mainboard.

•  Remove the 4 cables from the mainboard (use a flat tool to gently pry out the connectors, do not pull directly on the cables).

•  Remove the eddy current sensor cable, secured by 2 screws.

4Remove Mainboard and Feed Hall Board FPC

•  Remove the extruder mainboard from the toolhead.
•  When removing, carefully pull the FPC (flexible printed circuit) of the feed Hall board straight up and disconnect it (avoid shaking the FPC to prevent damage).

5Remove Five-way Assembly (Five-way and Sensor)

•  Remove the 2 screws that secure the five-way assembly to the extruder.
•  Gently lift the five-way assembly and place it above the toolhead.

6Separate and Replace Sensor from Five-way Assembly

•  Remove the 2 screws securing the sensor, and separate the old feed Hall board (sensor) from the five-way assembly.

•  Take out the new feed Hall board and peel off the blue protective layer from the FPC.
•  Press the FPC onto the Hall board (the FPC should align with the small groove between the two holes), and secure the new sensor back onto the five-way assembly with 2 screws.

7Reassembly

•  Place the five-way assembly back into the extruder and secure it with the 2 screws.

•  Place the mainboard back into the toolhead and reconnect the feed Hall board FPC.

•  Reconnect the 4 mainboard cables and the 2 screws for the eddy current sensor cable.

•  Reinstall the 3 black screws of the mainboard.

•  Reconnect the USB-C cable and tighten the 4 screws, finally replace the toolhead rear cover.

8Function Verification

•  Plug in and power on the printer.
•  Manually insert a piece of filament into any feed port until it bottoms out, and observe the icon in the lower right corner of the screen:
• o Filament inserted: Icon shows a green dot.
• o Filament unloaded: Green dot disappears.
•  Confirm that the green dot switches normally, indicating successful replacement of the filament sensor. It is recommended to perform a full calibration after completion.

1Workspace Preparation and Safe Power Off

•  Click control and raise the X-axis to create working space.
•  [Important] Always turn off the printer and unplug the power cord.
•  Ensure the toolhead has completely cooled down.

2Remove Front Cover, Silicone Sock, and Nozzle

•  Remove the front casing of the toolhead.
•  Remove the black silicone sock.

•  Open the metal buckle and remove the nozzle (hotend).

3Remove Extruder Screws and Pull Out Module

•  Remove the 4 screws as shown (two on top, two in the middle).

•  Carefully pull the extruder module forward slightly.
•  Caution: Do not forcefully pull the extruder module, as this may break the motor cable.

4Remove Toolhead Rear Cover, Connecting Cable, and Right Side Plate

•  Carefully pry open the bottom of the toolhead rear cover.
•  Carefully unplug the hotend assembly's connecting cable from its socket.
•  Remove the right side plate of the toolhead.

5Unplug Connecting Cable and Disassemble Hotend Assembly (Three Screws)

•  Unplug the connecting cable of the hotend assembly.

•  Use an Allen wrench to remove the three screws securing the hotend assembly.

•  Remove the hotend heating assembly.

6Install New Assembly and Reassemble

•  Place the new hotend assembly back into its position.
•  Reinstall the three screws to secure the hotend assembly.

•  Plug the cable connector back in correctly.
•  Push the extruder module back into place and tighten the 4 extruder screws.
•  Reinstall the nozzle, correctly buckle the clip, and put on the black silicone sock.

•  Reinstall the right side casing of the toolhead.

7Test

•  Plug in and power on the printer, go to Settings -> Maintenance -> Maintenance Mode -> Enable.
•  Heat the nozzle to 250 degrees and confirm that the temperature rises normally.

5Install New Assembly

•  Align the new hotend assembly with the holes.
•  Reinstall the three screws to secure it.
•  Plug the new assembly's cable connector into the slot.

6Reassembly and Test

•  Reinstall the nozzle and secure the metal clip.
•  Replace the black silicone sock.
•  Reinstall the front casing.
•  Plug in and power on, enable Maintenance Mode and heat to 250 degrees to confirm proper operation.

If you encounter a clog

Click control, raise the X-axis to move it away from the print bed, creating space for maintenance.
Press
Control -> XYZ -> Z Up

Open Maintenance Mode
Settings -> Page 2 -> Maintenance -> Maintenance Mode -> Enable

Remove the three screws securing the part cooling fan.

Go back to Control -> Nozzle -> Heat to 250 degrees

Wait 30 seconds.
Use needle-nose pliers to carefully remove the clogged material piece by piece.

Until the nozzle is exposed.
While heated, use needle-nose pliers to open the clip and remove the nozzle.
If the hotend assembly's connecting cable is not clogged,
you can remove all filament around the hotend assembly until no residue remains.

Finally, use a hairdryer to heat for 1-2 minutes until the filament starts to soften, then gently pull the filament away from the part cooling fan.

After cleaning, you can take out a new nozzle from the repair kit.
Reinstall the nozzle, secure it with the clip, and put on the hotend silicone sock.