How to fix a "Temperature Sensor Error" on a Markforged Desktop and Industrial 3d Printer

This article will walk through the process of diagnosing a "Temperature Sensor" Error on the Desktop and Industrial 3d Printers made by Markforged. The main causes of this error are an improperly seated ribbon cable, a ribbon cable that is no longer functional, and a bad print head. 

Verifying the Ribbon Cable is properly connected

1. Power down the printer and confirm that the ribbon cable is properly connected to the print head.

   1. Slide the black FFC Clip away from the metal bracket and onto the cable.

   2. Next, push the top and bottom buttons of the ribbon cable connector.
   3. Slowly and carefully remove the connector from the print head.
   4. To reseating the cable, carefully plug the ribbon cable back into position. The cable will snap back into position.
   5. Slide the black FFC Clip onto the metal bracket.
   6. Turn on the printer to verify that the error is cleared.
2. If the ribbon cable is properly connected but the issue persists:
   1. Continue Troubleshooting.

Testing the Print Head RTD

1. Power off and unplug the device.
2. Slide the FFC Clip off of the Print Head and gently unplug the Ribbon Cable as shown in the "Verifying the Ribbon Cable is properly connected" Section of this article.
3. Remove the two M3x6 SHCS screws and washers holding the Print Head Shield and Print Head PCB in place.
4. Note: The Desktop printers will not have the bracket that is held in place by the screws
5. Gently peel the Print Head Shield away from the Print Head
6. Use a multimeter to measure resistance values across each of the exposed pairs of RTD solder points.
   1. Point 1
   2. Point 2

At 21°C room temperature, the RTD resistance should be around 1081Ω. If the values are greater than 2290Ω or less 1019Ω, this indicates the Print Head is faulty (RTD failed) and will require replacement.

Reassemble the print head in the reverse order of the instructions above.

1. Fold the Print Head Shield up against the Print Head PCB
2. Install the two M3x6 screws and washers (torque to 30 in-oz) to hold the Print Head Shield and Print Head PCB in place
   1. Note: for Industrial printers, be sure to reinstall the FFC Bracket during this step
3. Plug the Ribbon Cable back into the Print Head and reinstall the FFC Clip
4. Plug back in and power back on the device

If your device is covered under warranty or a Digital Forge Complete Plan, please open a ticket with Hawk Ridge Systems. Provide a copy of the log files, the device ID and inform us you completed the troubleshooting steps. Please be sure to let us know what part failed, and include the resistance values for each RTD.

If your device is not covered under warranty, the replacement parts can be ordered through our store which can be found at https://hawkridgesys.com/store. You can also place your order by emailing our orders team at 3dporders@hawkridgesys.com. 

For further technical support, please contact Hawk Ridge Systems at 877.266.4469 for the U.S. or 866.587.6803 for Canada and 3dpsupport@hawkridgesys.com.