Vision Miner Wiki

Expansion Board Replacement

This guide covers replacing the expansion board (Duet 3 EXP3HC) on the Vision Miner 22IDEX V4. The expansion board drives the three Z motors, the bed and chamber heaters, the Z-probe, the chamber LEDs, and the HEPA fan, so a dead board takes all of these down at once. Before replacing it, work through the confirmation steps below - a board that shows no signs of life is rare, and in most cases the problem is elsewhere.

Before you begin - safety and risk

Read the Safety - Before You Begin article to understand the hazards involved in working on the Vision Miner 22IDEX V4 - including electrical, thermal, mechanical, and chemical risks. All procedures in this wiki are provided as recommendations only. By choosing to follow any procedure, you do so at your own risk.

Tools and Materials

  • Expansion Board
  • PH2 Phillips screwdriver (for the 24V power terminal screws)
  • 2 mm hex key (for the board mounting screws)
  • Permanent marker (for labeling the connectors)
  • Phone or camera (to photograph the wiring before disconnecting)

Confirming the Board Is Dead

The expansion board sits in the electronics bay below the mainboard. Both boards have power indicator LEDs - blue (24V), amber (12V), red (5V), green (3.3V) - and a DIAG status LED. On the expansion board the DIAG LED sits between the two CAN-FD connectors; on the mainboard it is next to the microSD slot. In normal operation both DIAG LEDs blink in sync, one second on, one second off. See Unresponsive Printer for the full LED reference.

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Work through these checks in order:

  1. Compare the DIAG LEDs. If the power LEDs on the expansion board are lit but its DIAG LED does not blink at all while the mainboard's DIAG blinks steadily, the board is not booting.
  2. Query the board over CAN. In the Web Interface console, send M122 B1. A dead board answers CAN response timeout: board 1. (Plain M122 should still return mainboard diagnostics normally.)
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  1. Press the reset button. The small reset button is in the upper-right corner of the expansion board, facing the small optocoupler Z-probe board. Press it briefly, then try pressing and holding it for 3-5 seconds. Watch the DIAG LED for any reaction.
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  1. Run the bare-board test. A short circuit in a connected peripheral (a pinched sensor wire, a faulty fan or heater) can force the board into protection so hard it refuses to boot. Power the printer off and unplug the power cord. Photograph the board, label every connector with a marker (the board is labeled next to each socket), and unplug everything from the expansion board except the 24V power input - including the CAN cable. Power the printer back on and watch the DIAG LED.
    • DIAG stays completely dark - the board itself is dead. Replace it using the procedure below.
    • DIAG comes back to life - the board is fine, and one of the disconnected peripherals has a short. Power off and reconnect them one at a time, powering on after each, until you find the one that kills the board, then contact our support team.
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Removing the Old Board

  1. Power off. Turn the printer off and unplug the power cord.
  2. Document the wiring. If you have not already done it during the bare-board test, photograph the board and label every connector with a marker so reassembly is unambiguous. The Wiring Schematic is the backup reference.
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  1. Disconnect the peripherals. Unplug all connectors from the board, including the CAN cable.
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  1. Disconnect the power. Unscrew the two screws securing the 24V power cables and free the cables.
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  1. Remove the board. Unscrew the four screws holding the board on its standoffs with the 2 mm hex key and take the board out.
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Installing the New Board

  1. Check the CAN address switches. Before mounting, make sure the CAN ADDR DIP switches on the new board match the old one: switch 1 up, the other three down (address 1). Do not change them afterwards.
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  1. Mount the board. Seat the new board on the four standoffs and fasten it with the four screws using the 2 mm hex key.
  2. Connect the power. Attach the 24V power cables with the two terminal screws.
  3. Reconnect the peripherals. Plug every connector back into its socket, following your photos and labels, and reconnect the CAN cable. Double-check against the Wiring Schematic.
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Verification

  1. Plug the printer in and power it on. The expansion board's DIAG LED should start blinking in sync with the mainboard's - one second on, one second off. The chamber lighting coming on is another quick sign the board is alive, since the LEDs are driven by it.
  2. In the console, send M122 B1 - the board should now return a full diagnostics report instead of a timeout. Send M115 B1 to check its firmware version.
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  1. If the firmware versions do not match the mainboard, update the expansion board: System > firmware directory, right-click Duet3Firmware_EXP3HC.bin, and choose Install. See SD Card & Firmware Recovery if anything goes wrong.
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FAQ

Support

If you could not find an answer here, reach out to our support team.

On this page

Tools and MaterialsConfirming the Board Is DeadRemoving the Old BoardInstalling the New BoardVerificationFAQSupport

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