¶ What it is
The printer cannot detect AMS during filament loading or printing. The LEDs in all four slots blink red (May blink white lights in the old AMS firmware version). No AMS tab is shown on the printer screen.
¶ Troubleshooting
TURN OFF the printer before any troubleshooting procedure.
¶ 1. Pin loose check
The Bambu 4-pin & 6-pin Bus cables connect AMS, filament buffer, and the printer, which provides power from the printer to AMS and transfers signals among these 3 components.
Check the pin loose and replug as needed. Then check whether the AMS can be detected by the printer.
¶ 2. Pin check
Check whether the Pins of the Bambu 4-pin & 6-pin Bus cable (cables connecting AMS—buffer—printer) are open as below:
¶ 3. Connection check
- Check if the bus cable inside the AMS is loose:
- It is recommended to shake or bend the 4-pin and 6-pin plugs and cable slightly, or pull out the plugs a little bit (do not pull them out completely) to see if the AMS can be detected for a short time so that we can narrow the fault to the plug/cable;
¶ 4. Measure the resistance values
If you have a multimeter, make sure the 4-pin and 6-pin cables are connected properly, then use the multimeter to measure the resistance of the AMS, the printer, and the 4-pin and 6-pin cables (please keep the printer off).
The normal resistance values for X1C, P1P, and P1S (with only one AMS connected) are as follows:
| pin-pin | AMS port | Printer port | 4-pin cable connects the buffer | 4-pin cable connects the printer | 6-pin cable connects the buffer | 6-pin cable connects the AMS | 4-pin cable connects the AMS Hub | 6-pin cables connect the AMS Hub |
| GND-sigA | 4~5kΩ | 4~5kΩ | 4~5kΩ | 4~5kΩ | 4~5kΩ | 4~5kΩ | 2~2.5kΩ | 2~2.5kΩ |
| GND-sigB | 4~5kΩ | 4~5kΩ | 4~5kΩ | 4~5kΩ | 4~5kΩ | 4~5kΩ | 2~2.5kΩ | 2~2.5kΩ |
| sigA-sigB | 8~10kΩ | 8~10kΩ | 8~10kΩ | 8~10kΩ | 8~10kΩ | 8~10kΩ | 4~5kΩ | 4~5kΩ |
The normal resistance values for X1E (with only one AMS connected) are as follows:
| pin-pin | AMS port | Printer port | 4-pin cable connects the buffer | 4-pin cable connects the printer | 6-pin cable connects the buffer | 6-pin cable connects the AMS | 4-pin cable connects the AMS Hub | 6-pin cables connect the AMS Hub |
| GND-sigA | 4~5kΩ | 2~2.5kΩ | 4~5kΩ | 2~2.5kΩ | 2~2.5kΩ | 4~5kΩ | 2~2.5kΩ | 2~2.5kΩ |
| GND-sigB | 4~5kΩ | 2~2.5kΩ | 4~5kΩ | 2~2.5kΩ | 2~2.5kΩ | 4~5kΩ | 2~2.5kΩ | 2~2.5kΩ |
| sigA-sigB | 8~10kΩ | 4~5kΩ | 8~10kΩ | 4~5kΩ | 4~5kΩ | 8~10kΩ | 4~5kΩ | 4~5kΩ |
¶ Measure the resistance of both ends of the 4-pin port on the printer and the 4-pin cable.
First, disconnect the 4Pin cable from the printer and measure the resistance of the printer's 4-pin interface and 4-pin cable, as shown below.
The normal resistance measurement results for the 4-pin port on the printer are as follows:
| Pin-Pin | X1C/P1P/P1S | X1E |
| GND-sigA | 4~5kΩ | 2~2.5kΩ |
| GND-sigB | 4~5kΩ | 2~2.5kΩ |
| sigA-sigB | 8~10kΩ | 4~5kΩ |
The normal resistance measurement results for the 4-pin cable connected to the buffer are as follows:
| Pin-Pin | X1C/P1P/P1S | X1E |
| GND-sigA | 4~5kΩ | 4~5kΩ |
| GND-sigB | 4~5kΩ | 4~5kΩ |
| sigA-sigB | 8~10kΩ | 8~10kΩ |
Then connect the 4-Pin cable back to the printer, unplug the 4-pin cable from the buffer, and continue to measure the resistance of the 4-pin cable at the other end (removing the buffer from the printer makes it easier to unplug the cable).
The normal resistance measurement results for the 4-pin cable connected to the printer are as follows:
| Pin-Pin | X1C/P1P/P1S | X1E |
| GND-sigA | 4~5kΩ | 2~2.5kΩ |
| GND-sigB | 4~5kΩ | 2~2.5kΩ |
| sigA-sigB | 8~10kΩ | 4~5kΩ |
¶ Measure the resistance of both ends of the 6-pin port on the AMS and the 6-pin cable.
Next, connect the 4-Pin cable back to the buffer, unplug the 6-Pin cable from the AMS, and measure the resistance of the AMS 6-Pin port (both ports are the same) and the 6-Pin cable.
The normal resistance measurement results for the 6-pin port on the AMS are as follows:
| Pin-Pin | X1C/P1P/P1S | X1E |
| GND-sigA | 4~5kΩ | 4~5kΩ |
| GND-sigB | 4~5kΩ | 4~5kΩ |
| sigA-sigB | 8~10kΩ | 8~10kΩ |
The normal resistance measurement results for the 6-pin cable connected to the buffer are as follows:
| Pin-Pin | X1C/P1P/P1S | X1E |
| GND-sigA | 4~5kΩ | 2~2.5kΩ |
| GND-sigB | 4~5kΩ | 2~2.5kΩ |
| sigA-sigB | 8~10kΩ | 4~5kΩ |
Finally, unplug the 6-Pin cable from the buffer and measure the resistance at the other end of the 6-Pin cable (removing the buffer from the printer makes it easier to unplug the cable).
The normal resistance measurement results for the 6-pin cable connected to the AMS are as follows:
| Pin-Pin | X1C/P1P/P1S | X1E |
| GND-sigA | 4~5kΩ | 4~5kΩ |
| GND-sigB | 4~5kΩ | 4~5kΩ |
| sigA-sigB | 8~10kΩ | 8~10kΩ |
¶ Measure the resistance between the AMS mainboard and the MC board.
If an abnormal resistance value is measured in the above steps, you can determine where in the AMS/printer/4&6pin cable/buffer the fault is causing the AMS to be undetectable.
Measure the resistance of the AMS mainboard
If the resistance of the AMS 6-pin port is abnormal, you can disassemble AMS (please refer to this wiki) and further measure the resistance of the pins of the Bus and power cables connected to the mainboard to see whether the mainboard is faulty:
The normal resistance measurement results for the bus and power cable are as follows:
| Pin-Pin | X1C/P1P/P1S | X1E |
| GND-sigA | 4~5kΩ | 4~5kΩ |
| GND-sigB | 4~5kΩ | 4~5kΩ |
| sigA-sigB | 8~10kΩ | 8~10kΩ |
- If the resistance measured on the bus and power cable port connected to the mainboard is normal, it may indicate a faulty AMS power board that needs to be replaced.
- If the resistance measured on the bus and power cable port connected to the mainboard is abnormal, it may indicate a faulty AMS mainboard.
Measure the resistance of the MC board
If the measured resistance of the printer's 4-pin port is abnormal, it may be the fault of the AMS interface board or the MC board. You can remove the back cover of the printer, unplug the 6pin cable from the AMS interface board (please refer to this wiki), and measure the resistance of the 6pin cable connected to the MC board to see whether the MC board is faulty:
The normal resistance measurement results for the 6-pin cable connected to the MC board are as follows:
| Pin-Pin | X1C/P1P/P1S | X1E |
| GND-sigA | 4~5kΩ | 4~5kΩ |
| GND-sigB | 4~5kΩ | 4~5kΩ |
| sigA-sigB | 8~10kΩ | 8~10kΩ |
- If the resistance measured on the 6-pin cable connected to the MC board is normal, it may indicate a faulty AMS interface board that needs to be replaced.
- If the resistance measured on the 6-pin cable connected to the MC board is abnormal, it may indicate a faulty MC board that needs to be replaced.
For X1E, if the resistance measurements mentioned above are all normal, please refer to the following images. First, remove the air duct (left image), and then measure the resistance of the Network interface and AMS interface board port on the heating module control board (right image).
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The normal resistance measurement results for the Network interface and AMS interface board port on the heating module control board are as follows:
| Pin-Pin | X1E |
| GND-sigA | 4~5kΩ |
| GND-sigB | 4~5kΩ |
| sigA-sigB | 8~10kΩ |
If the measured resistance is abnormal, it may indicate a need to replace the heating module control board.
¶ Note
There are 8 sets of resistance value data above, as shown in the following figure. If the measured resistance value of any part is abnormal, it indicates that this part is faulty. Please measure and record them regarding the following picture, and then contact the customer support team for assistance.
Here is a sample table for recording resistance measurements:
| pin-pin | AMS port | Printer port | 4-pin cable connects the buffer/AMS hub | 4-pin cable connects the printer | 6-pin cable connects the buffer/AMS hub | 6-pin cable connects the AMS | MC board | AMS mainboard |
| GND-sigA | ||||||||
| GND-sigB | ||||||||
| sigA-sigB |
¶ Error message
HMS_0700_5000_0002_0001: AMS1 communication is abnormal; please check the connection cable.
The error code below shows the same issue with different force sensors:
0700-5000-0002-0001
¶ End Notes
We hope that the detailed guide we shared with you was helpful and informative.
If you have completed the above steps but the issue still persists, please record a video demonstrating AMS and printer working condition. After that, allow the printer to sit idle for 10 minutes, upload the recorded video, and submit the printer's log file with your resistance measurements results. Finally, please submit a technical service ticket for further troubleshooting and problem resolution.
We want to ensure that you can perform it safely and effectively. If you have any concerns or questions regarding the process described in this article, we encourage you to reach out to our friendly customer service team before starting the operation. Our team is always ready to help you and answer any questions you may have.
Click here to open a new ticket in our Support Page.
We will do our best to respond promptly and provide you with the assistance you need.