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Small rectangular sensor module with cable and connector, matte black finish

Monoprice Inc.

Monoprice 139172 Door Open Sensor for Maker Ultimate 2 3d printers accessory

SKU CH-PG8N-QXB41

Replacement door-open sensor designed for the Monoprice Maker Ultimate 2 3D printer

  • Type3D Printer
  • FeaturesTechnical assistance can be reached via live chat at Monopri
  • Designed specifically for Maker Ultimate 2 printer
  • Replaces faulty sensor to restore door detection
  • Manufacturer part 139172 ensures exact fit
  • Safety reminder: disconnect power before installation
  • Technical support available via phone 877-271-2592

Replacement Door Sensor for Maker Ultimate 2

The Monoprice 139172 is a direct replacement door open sensor engineered for the Monoprice Maker Ultimate 2 3D printer. It restores the safety interlock that pauses or stops a print when the enclosure door is opened. The part arrives new and ready for installation by experienced users.

Suited for owners needing a safety interlock repair

This sensor suits Maker Ultimate 2 owners whose original door switch has failed or been damaged during maintenance. It is not for users of other Monoprice models or third‑party printers, as the mounting and wiring are specific to the Ultimate 2. Builders without confidence in electrical disassembly should seek professional assistance.

Consistent operation during long print sessions

Under sustained load the sensor maintains its switching state reliably throughout multi‑hour prints, preventing accidental door openings from ruining large jobs. The simple mechanical design has no active electronics to overheat, so performance does not degrade as the enclosure temperature rises. Regular inspection keeps the safety function dependable.

Highlights

  • Designed specifically for Maker Ultimate 2 printer
  • Replaces faulty sensor to restore door detection
  • Manufacturer part 139172 ensures exact fit
  • Safety reminder: disconnect power before installation
  • Technical support available via phone 877-271-2592

Specifications

BrandMonoprice
Model139172
Part Number139172
Type3D Printer
FeaturesTechnical assistance can be reached via live chat at Monoprice.com Monday through Friday 6am - 6pm PST, via email at [email protected] , or via phone at 877-271-2592 Monday through Friday 6am - 5pm PST.

Questions about this item

Which printer model must I own for the 139172 door sensor to function?

The sensor is designed for the Monoprice Maker Ultimate 2 3D printer, also referenced as model 36045.

Will this sensor connect to the existing wiring harness on my Ultimate 2 without modification?

It is a direct replacement part for the Ultimate 2, so it fits the original mounting points and connector.

How can I verify the sensor is working after installation?

Open the printer door while the machine is powered on; the control panel should immediately report a door-open fault and pause any active print.

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