This article offers troubleshooting methods for common AMS loading and unloading failures. When you encounter issues with AMS loading and unloading, refer to this article for troubleshooting based on error messages and fault symptoms. Before troubleshooting, familiarize yourself with the main functions and workflow of AMS by referring to this Wiki:
AMS main functions and workflow introduction | Bambu Lab Wiki
If you encounter this error, it means that the AMS internal hub hall switch is unable to detect the filament. If the filament is not being pushed out of the PTFE tube, it indicates a potential failure in the loading process due to one of the following reasons:
(1) Troubleshooting of feeder hall switch
If the filament is inserted into the feeder but the feeder fails to detect it, the loading failure may be due to an abnormal feeder hall switch. Here is an overview of the feeder LED status:
AMS LED Status Troubleshooting | Bambu Lab Wiki
Note: If the feeder hall switch is abnormal and the filament insertion is not detected, the load button on the screen will not light up.
Troubleshooting method:
When the filament is inserted into the feeder, the feeder hall switch detects the insertion of the filament, and at the same time the feeder LED light will be on. When the filament is pulled out of the feeder, the hall switch detects the filament is pulled out and the feeder LED light will turn off. Therefore, you can determine if the feeder hall switch is functioning properly by inserting or pulling out the filament.
(2) Troubleshooting of feeder
The following picture shows the normal working condition of the feeder, when the filament is inserted into the feeder, the feeder LED white light is on and the feeder motor rotates to feed the filament into the AMS.
If, when the filament is inserted into the feeder, the feeder LED white light turns on to detect the filament but the filament is not being fed into the AMS, please record a video of the feeder and contact the after-sales service.
When the feeder is working properly, but when clicking "loading" or reading RFID, the filament is not pushed out of the PTFE tube on the back of the AMS. This may be a loading failure due to an AMS internal filament hub hall switch.
Troubleshooting steps:
You can follow these steps to check the functionality of the AMS internal filament hub hall switch:
1. Remove the PTFE tube
2. Unscrew the two fixing screws on the AMS main frame
3. Turn the AMS main frame over
Note: Please flip the AMS main frame over carefully to prevent pulling the cable off!
4. Insert the filament into the AMS internal filament hub and observe the feeder LED. If the LED emits a red light, it indicates that the hall switch is functioning properly as it detects the presence of the filament.
Note: During the testing process, it is advisable to repeat the procedure multiple times to determine if the feed failure is indeed caused by an abnormality in the AMS internal filament hub hall switch.
If there are no abnormalities in the feeder or the AMS internal filament hub, and the feeder motor does not respond when the loading button is clicked, it could indicate an issue with the buffer. For troubleshooting steps, please refer to the following Wiki:
The filament buffer signal lost, the cable or position sensor may malfunction | Bambu Lab Wiki
This error occurs when the filament has been dispensed from the AMS filament hub, but the extruder hall switch fails to detect it. The loading failure may be attributed to the following reasons:
When the filament is tangled or the spool is jammed, it will cause the loading failure, please check if the filament is tangled or the spool is jammed.
If the spool can rotate normally, please ensure that the filament encounters resistance at the indicated position in the following figure, as this can be a cause of loading failure.
If the filament encounters resistance feeding to the extruder at position 1 or 2, remove the PTFE tube to see if the feed is failing due to a damaged pneumatic connector. If the pneumatic connector is damaged, it will need to be replaced.
If the filament hub hall switch is functioning properly, the feed failure may be caused by the following reasons:
(1) Abnormal of the AMS internal filament hub motor
When the AMS internal filament hub hall switch detects the filament, but at this time, it may not be able to push the filament out of the AMS because the filament hub motor is not rotating. If you encounter this issue, please follow the steps in the figure below to re-plug the filament hub motor connecting cables. If the motor continues to malfunction, please contact our after-sales service for further assistance.
Replacing the AMS internal filament hub | Bambu Lab Wiki
(3) The AMS active extrusion wheel slipping
If there is no resistance in the PTFE tube connector preventing the filament from feeding to the extruder, the filament stops on its way to the extruder. You can verify whether there is any visible wear on the backside of the filament (the side that is coiled on the spool) by pulling out the filament from the AMS and referring to the following figure. If there is wear, it is possible that the feed is failing due to the AMS active extrusion wheel slipping and thus wearing out the filament. You can refer to this Wiki to fix the problem by replacing the AMS active extrusion wheel: Replace the AMS active extrusion wheel assembly | Bambu Lab Wiki
If the filament can be fed to the extruder, but still shows a failure to feed into the extruder, it is possible that the filament is not being detected due to a faulty extruder hall switch.
Extruder hall switch failure troubleshooting
You can switch the display to the "Temperature/Axis" and watch for the green dot light up as shown below. If the green dot is on, the extruder hall switch detects the filament.
You can open Bambu Studio switch the display to the "Device" and watch for the green dot to light up as shown below. If the green dot is on, the extruder Hall switch detects the filament.
According to the above method, if there is no filament in the extruder and the green dot in the figure is always on, the feed failure may be caused by the following two reasons:
You can remove the extruder from the tool head first to judge whether there is broken filament in the extruder, if there is broken filament in the extruder, please refer to this Wiki to clean it:
Extruder Clog | Bambu Lab Wiki
If there are no breaks in the extruder, refer to this Wiki to check that the Hall switch magnet is not springing back properly:
HMS_0700_2000_0002_0004: The AMS slot1's filament may be broken in the tool head | Bambu Lab Wiki
When AMS successfully feeds filament to the extruder and the extruder hall switch detects that filament is being fed, but reports an error "Fail to extruder filament",it is usually due to the extruder gears failing to grip the filament properly. This can be caused by several factors:
When the extruder is clogged, the new filament cannot be gripped by the extruder because there is still residual filament obstructing the extruder's pathway. As a result, an error message that the filament extrusion failed will appear. To resolve this issue, please refer to the following wiki:
Extruder Clog | Bambu Lab Wiki
When the extruder hall switch is functioning properly and the filament is being fed to the tool head, but the extruder fails to grip and you can print with an external filament. It is possible that a feed failure is occurring due to an abnormal buffer signal. In such cases, you can troubleshoot the issue by referring to the following Wiki:
If the feed failure is not caused by the previously mentioned issues, it could be due to an abnormal speed of the AMS filament hub motor, leading to the feed failure. In such cases, it is recommended to upload the printer log and contact the after-sales service for assistance in resolving the problem.
How to update log files to an existing ticket | Bambu Lab Wiki
How to upload the log files of P1 series | Bambu Lab Wiki
When encountering an unloading failure with AMS, the first step is to observe whether the filament is exiting from the extruder.
This error occurs when the extruder still detects filament inside even after the AMS unloading process has been running for a period of time. Several possible reasons for this issue include:
When experiencing unloading failure and the filament cannot be successfully extruded from the extruder, it is likely due to a clogged extruder. To resolve this issue, please refer to the following Wiki:
Extruder Clog | Bambu Lab Wiki
If the filament has been successfully extruded from the extruder, but the system still indicates a failure to exit the extruder. Please refer to the same steps as above Extruder hall switch failure troubleshooting method to check whether the green dot in the extruder icon is illuminated.
You can switch the display to the "Temperature/Axis" and watch for the green dot light up as shown below. If the green dot is on, the extruder hall switch detects the filament.
You can open Bambu Studio switch the display to the "Device" and watch for the green dot to light up as shown below. If the green dot is on, the extruder Hall switch detects the filament.
According to the above method, if there is no filament in the extruder and the green dot in the figure is always on, the feed failure may be caused by the following two reasons:
You can remove the extruder from the tool head first to judge whether there is broken filament in the extruder, if there is broken filament in the extruder, please refer to this Wiki to clean it:
Extruder Clog | Bambu Lab Wiki
If there are no breaks in the extruder, refer to this Wiki to check that the Hall switch magnet is not springing back properly:
HMS_0700_2000_0002_0004: The AMS slot1's filament may be broken in the tool head | Bambu Lab Wiki
This error pops up when the extruder hall switch detects that the filament has exited the extruder after a period of time of unloading, but the AMS internal filament hub hall switch still detects the filament (a complete unloading process will pull back the filament inside the AMS). This can be caused by the following:
If the spool is stuck or the filament is tangled, it can lead to a failure in the unloading process. We recommend that you start by checking if the spool is stuck or if there are any tangles in the filament.
(1) The PTFE tube bent too much
Excessive bending of the PTFE tube above the tool head can create excessive resistance for the filament inside the tube. This resistance prevents the filament from being pulled back, resulting in a failure to unload.
You can click here to download a PTFE tube bracket that can be mounted above the tool head to prevent the PTFE tube connected to the tool head from bending too much.
The PTFE tube bracket is installed as depicted below:
(2) AMS internal filament hub debris accumulation
When using AMS for an extended period, excessive accumulation of filament debris inside the filament hub can result in increased resistance and potential unloading failure.
You can refer to this Wiki for instructions on how to clean the inside of the AMS internal filament hub:
Dismantling and cleaning the filaments hub | Bambu Lab Wiki
(3) Unloading failure of special filament
If you encounter a specific filament unloading failure, such as PLA-CF, we recommend using the spool holder positioned at the back of the printer when printing the filament.
If you notice excessive noise from the feeder while using the AMS for unloading, it could be because the active support sleeve is not fully inserted into the AMS main frame. As a result, only the yellow gear of the feeder rotates, while the black active support sleeve remains stationary. This prevents the spool from rotating properly and can lead to unloading failures.
The image below illustrates the process of snapping the active support sleeve into the AMS main frame:
2.2.4 There is a broken filament inside the filament hub
If the filament has already exited the feeder, but the AMS continues to unload and the feeder LED light remains red (as depicted in the figure below), it is possible that there is a broken filament inside the AMS internal filament hub, causing the unloading failure. Please refer to this wiki for instructions on how to disassemble the AMS internal filament hub for cleaning:
Dismantling and cleaning the AMS filaments hub | Bambu Lab Wiki