¶ Problem Description
- Heated bed displays a negative temperature
- Error messages on the screen: "Heated Bed Underheat", "Heated Bed Not detected"
- Error 515-10 or 515-6 appears on the touchscreen
¶ Possible Causes
- Heated bed cable malfunction
- Heated bed extension cable (7P cable) malfunction.
- Mainboard heated bed port malfunction.
¶ Troubleshooting
¶ Step 1
Check whether the heated bed cable and the heated bed extension cable are securely connected and properly aligned. If the connections are fine, proceed to the next step.
¶ Step 2
Check whether the connection between the heated bed extension cable and the main control board is secure and correct. If the connection is fine, proceed to the next step.
¶ Step 3
Gently shake the heated bed cable and observe if the temperature displayed on the screen fluctuates. If it does, this indicates a poor connection, and the heated bed cable may be faulty.
If there is no fluctuation, proceed to the next step.
¶ Step 4
Use a multimeter to measure the resistance of the heated bed cable to check if the heated bed or the cable is faulty.
Demonstration video for measuring the resistance of the heated bed cable
- Set the multimeter to measure resistance (Ω). Ensure that the multimeter is set to a resistance range greater than kΩ when testing the heated bed cable
- Place the probes of the multimeter at the connector pins of the heated bed cable and measure the resistance across the combinations marked in the diagram below.
The resistance values shown in the diagram are for a room temperature of approximately 26°C. The actual resistance value may vary depending on the room temperature. Refer to the link below to find the correct resistance value based on the actual room temperature:
If the resistance between pin 1-2 or pin 1-3 is infinite, or if it doesn't match the normal resistance value, it could indicate a fault with the heated bed or the heated bed cable.
- Follow the steps below to further check whether the issue is with the heated bed cable or the heated bed itself.
- Use an H2.0 screwdriver to remove the screws shown in the image below.
- Check the solder joints on the heated bed cable for any signs of cold soldering or detachment. If you find any issues and have the ability to solder, you can re-solder the connections to ensure a secure and proper connection.
If the resistance of the heated bed cable is abnormal, and shaking the cable does not cause any change in the heated bed temperature on the screen, and there are no signs of cold solder joints, then the issue is likely with the heated bed itself.
If the resistance of the heated bed cable is normal, please proceed to the next step.
¶ Step 5
Use a multimeter to measure the resistance of the heated bed extension cable (7P cable) to check if the the cable is faulty.
Demonstration video for measuring the resistance of the heated bed extension cable (7P cable)
The measurement method and resistance values are the same as in step 4; the only difference is that you will be measuring a different cable. Please refer to the same process in step 4.
If the resistance between pin 1-2 or pin 1-3 is infinite, or if it doesn't match the normal resistance value, it could indicate a fault with the heated bed extension cable (7P cable).
¶ Step 6
If the resistance values of both the heated bed cable and the extension cable (7P cable) are normal, then the issue is likely with the main control board.
¶ Reach out to Snapmaker Support
After following the troubleshooting steps, if you find it difficult to resolve your issue, kindly submit a support ticket through https://snapmaker.formcrafts.com/support-ticket and share your troubleshooting results with some pictures/videos.
Our dedicated support team will be more than willing to assist you in resolving the issue.