The actual heat bed temperature is displayed as 0 ℃, or the heatbed does not heat up after setting a temperature.
For the A1, when the heat bed is not heating up or when the heating bed temperature is 0, it is recommended to prioritize checking whether the heat bed heating unit is functioning properly. This can be determined by measuring the resistance of the hotbed using a multimeter to identify the location of the malfunction.
IMPORTANT!
It's crucial to power off the printer before performing any maintenance work on the printer and its electronics, including tool head wires, because leaving the printer on while conducting such tasks can cause a short circuit, which can lead to additional electronic damage and safety hazards.
When you perform maintenane or troubleshooting on the printer, you may be required to disassemble some parts, including the hotend. This process can expose wires and electrical components that could potentially short circuit if they come into contact with each other or with other metal or electronic components while the printer is still on. This can damage the electronics of the printer and cause further damage.
Therefore, it's essential to switch off the printer and disconnect it from the power source before doing any maintenance work. This will prevent any short circuits or damage to the printer's electronics. By doing so, you can avoid potential damage to the printer's electronic components and ensure that the maintenance work is performed safely and effectively.
If you have any concerns or questions about following this guide, open a new ticket in our Support Page and we will do our best to respond promptly and provide you with the assistance you need.
During the troubleshooting process, please avoid applying an external force to the heatbed cable to prevent any impact on its lifespan.
This article only provides guidelines and precautions for measuring heat bed resistance. For guidelines on disconnecting the motor connection cable from the AC board, please refer to “Step 2- Disconnect the cables” of the “A1 Disassembly” in A1 Installation Tutorial | Bambu Lab Wiki.
Note: In this step, there is no need to open the Z-motor cable cover of the cable box. Simply slide the cable box to disconnect the USB cable.
After disconnecting the connection cable, use an H2.0 hex key to remove the 10 screws indicated by red dots on the baseplate shown in the diagram below. Lift and remove the printer's baseplate from the left edge, exposing the measurement location of the AC board as illustrated. The position of the AC board is shown in the diagram.
After removing the bottom cover, please first check if the temperature sensor (NTC sensor)plug for the heatbed is loose, as previous cases have shown that it may become detached during transportation. If you find the plug loose, please reinsert it into the socket according to its orientation, then reinstall the bottom cover and restart the printer to see if the issue has been resolved.
Note: It is not necessary to remove the heat bed assembly from the printer during resistance measurement.
If the resistance measured at this point is around 100 kΩ (it may vary with the ambient temperature; a slight deviation is acceptable, and the measured value in the graph is 102.7 kΩ), the heat bed's NTC sensor and temperature sensing cables are functioning properly.
Important Note: To perform the measurement at this point, use a tweezer to disconnect the heat bed NTC cable. As shown in the diagram, the measurement location is at the red and blue wire connection ports on the NTC cable.
(This diagram is for reference purposes only to indicate the measurement points for heat bed resistance. It is not necessary to remove the components from the printer base during the measurement process)
If the resistance measured at this point is 45Ω~50Ω (it may vary with the ambient temperature; a slight deviation is acceptable, and the measured value in the graph is 47.5 Ω), it indicates that the heat bed heating part and power cables are functioning properly.
Important Note 1: The power connection location on the AC board is shown in the diagram.
(This diagram is for reference purposes only to indicate the measurement points for heat bed resistance. It is not necessary to remove the components from the printer base during the measurement process)
Important Note 2: For convenience during measurement, you can use a tweezer to remove the insulation sleeve wrapped around the terminal block, as shown in the diagram. It is not necessary to remove the heating cables during measurement.
If both resistance values mentioned above are normal, the entire heat bed assembly (aluminum bed, heating cables, NTC sensor, and cable) functions properly.
In the case of abnormal heating or temperature issues with the heat bed, it is recommended to prioritize replacing the AC board.
However, replacing the heatbed assembly is necessary if both resistance values are abnormal.
We hope that the detailed guide we shared with you was helpful and informative.
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.