The motherboard is the main electronics module on the Form 4 that controls the various subsystems. The motherboard attaches to the printer and is located behind the right side panel. A malfunctioning motherboard may prevent the printer from printing properly.

Use this guide to replace the motherboard.

Estimated time: 2 hours

Overview: Prepare the printer and a dust-free workspace for replacing the motherboard.

Step 1: Remove the build platform

Remove the build platform first to avoid dripping resin onto the Light Processing Unit (LPU).

Step 2: Remove the resin cartridge

Remove the resin cartridge and close the vent cap to prevent resin from dripping off of the bite valve and into the printer.

Step 3: Remove and store the resin tank and mixer

Unlatch the mixer and resin tank. Remove the resin tank and cover it with its lid. Set the tank aside on a clean, flat surface.

Step 4: Prepare the workspace

Clear a workspace around your printer. Ensure that the workspace is well-ventilated and free of dust. Prepare additional space for storing the exterior panels, the LPU, the resin tank latches, the touchscreen, and the nest of the printer during maintenance.

Step 5: Clean the printer

Open the printer cover and clean any resin pooled on and around the LPU with non-abrasive wipes. Dampen the wipes with isopropyl alcohol if necessary to fully remove the resin.

Step 6: Unplug the printer

Disconnect the power cable before continuing with maintenance. Do not perform maintenance on the printer while it is connected to power. Wait five minutes after disconnecting the printer from power before proceeding.

Step 7: Check the motherboard fasteners

Overview: Remove the exterior panels and the rear mesh filter to access the motherboard.

Step 4: Remove the rear mesh filter

Remove the magnetic rear mesh filter and set it aside.

Overview: Loosen the housing screws and remove the LPU.

Step 3: Disconnect the tank heater cable

Release the tank heater cable by squeezing the tab on the connector and pulling directly away from the LPU. Do not pull on the cable itself.

Step 4: Remove the LPU

Remove the LPU from the printer and set it aside.

Overview: Locate the retaining tab, remove the pin and spring, and remove the resin tank latches.

Step 2: Remove the pin and spring

While pressing down on the retaining tab with the 2.5 mm hex driver, use the 2 mm ball-end hex driver to push the pin through the bracket. You may need to use a moderate amount of force to fully push the pin out of its bracket. Once the pin is removed, the spring separates from the bracket. Set the spring and pin aside.

Step 3: Remove the second pin

Repeat steps 1–2 to remove the second pin from the resin tank latch. Note that there is only one spring per latch. The pin with the spring is located closer to the front of the printer.

Step 4: Remove the second resin tank latch

Repeat steps 1–3 to remove the second resin tank latch. Set the resin tank latches aside.

Overview: Remove the touchscreen assembly from the printer.

Step 5: Rotate the printer

Close the printer cover and carefully lay the printer on its back with the cover facing upwards.

Step 6: Loosen the bottom panel screws

Use a 2.5 mm hex driver to loosen the two screws securing the bottom panel. Do not fully remove the screws.

Step 9: Disconnect the touchscreen ribbon cable

Rotate the black plastic tab on the connector away from the touchscreen assembly to unlatch the touchscreen ribbon cable. Do not pull on the cable. Once the black tab is properly released, the cable slides out of the connector with minimal force. Set the display assembly aside.

Overview: After removing the LPU, remove the nest.

Step 1: Remove the side screws

There are two side screws each on the left and right sides of the printer that secure the nest to the printer. Using a 2.5 mm hex driver, remove the side screws. Set the screws aside.

Step 4: Disconnect the interlock cables

Unplug the cables from the cover interlock boards attached to the nest. Set the nest aside.

Overview: After removing the nest, remove the lower back panel.

Step 1: Remove the side screws

Using a 2.5 mm hex driver, remove the two screws on the left side and the two screws on the right side that secure the lower back panel to the printer. Set the screws aside.

Step 3: Remove the lower back cover

Remove the lower back cover and set aside.

Overview: After removing the exterior panels, remove the motherboard.

Overview: After removing the old motherboard, connect and install the replacement.

Step 1: Install the motherboard mounting screws

Position the motherboard on the right side of the printer so the screw holes are aligned. Using a 2.5 mm hex driver, install the four hex screws on the left side of the motherboard. Using a 2 mm hex driver, install the two hex screws on the back of the printer. Do not overtighten the screws.

Step 2: Connect the cables to the motherboard

Reconnect all cables to the motherboard. Use the nu mbered labels on the cables and the matching labels printed on the motherboard.

Overview: After replacing the motherboard, install the lower back panel.

Step 3: Install the side screws

Using a 2.5 mm hex driver, install the two screws on the left side and the two screws on the right side that secure the lower back panel to the printer.

Overview: After installing the lower back panel, install the nest.

Step 1: Position the nest

Lower the nest down onto the printer. Note that the front edge has a gasket and will provide some resistance. Ensure that the flanges on the rear of the nest are inserted into the corresponding slots in the lower back panel.

Step 3: Install the side screws

Use a 2.5 mm hex driver to install the two screws on the left side and the two screws on the right side that secure the nest to the printer.

Step 4: Connect the cover interlock cables

Connect the cover interlock cables on each side of the nest. The plastic tabs should click into place to secure the connection.

Overview: After installing the nest, reinstall the touchscreen assembly.

Step 1: Connect the touchscreen ribbon cable to the display assembly

Slide the ribbon cable into the connector on the touchscreen assembly. Make sure the cable is inserted evenly. The blue mark should face upward.

Step 2: Secure the ribbon cable

Flip down the black tab on the connector to secure the cable to the touchscreen assembly. Take care not to pull on the cable during installation.

Step 3: Position the touchscreen assembly for installation

Position the touchscreen assembly on the printer. Make sure that the sheet metal tabs are positioned outside of the printer frame and that they align with the screw holes on the printer. Take care not to crush or fold the touchscreen ribbon cable.

Step 4: Tighten the bottom panel screws

Make sure that the two bottom tabs of the touchscreen assembly can slide into the printer before tightening the screws. Use a 2.5 mm hex driver to tighten the two screws that secure the bottom panel to the printer.

Step 5: Set the printer upright

Rotate the printer to sit upright.

Overview: After reinstalling the touchscreen assembly, reinstall the resin tank latches.

Step 1: Pre-assemble the resin tank latch

The resin tank latch needs to be partially assembled before installing it onto the printer. Slide the metal pins into the bracket from the inside of the latch. Insert the spring as shown with the shorter leg pressed against the latch. The pin threads through the spring. Leave space in the bracket for installation.

Repeat the previous step to thread the pin through the second bracket. Note that there is only one spring per latch, and the spring should be positioned such that it will be towards the front of the printer once the latch is installed.

Step 5: Install the second pin

Repeat the previous step to install the second pin in the resin tank latch. Note that there is only one spring per latch, located towards the front of the printer.

Step 6: Repeat

Repeat steps 2-4 on the second resin tank latch.

Overview: After replacing the motherboard, connect and reinstall the LPU.

Step 1: Connect the tank heater cable

Position the LPU so the connector ports are oriented towards the back of the printer. Plug the tank heater cable into the connector on the LPU. The plastic tab should click into place to secure the cable.

Step 2: Connect the HDMI cable

Plug the HDMI cable into the port on the LPU. Ensure that the two prongs on the plastic retaining clip snap into place.

Step 3: Mount the LPU

Ensure that the optical cavity and LPU are free from dust and debris. Place the LPU onto the optical cavity and align the screw holes.

Overview: Install the left, right, and upper back exterior panels. Also install the rear mesh filter.

Step 1: Reinstall the rear mesh filter

Reattach the mesh filter to the printer, ensuring that it is aligned with the air intake vents.

Overview: After installing the new motherboard, power on the printer and perform final checks.

Step 1: Power on the printer

Close the printer cover and connect the power cable to the printer and the power supply. Turn on the switch at the back of the printer. The printer turns on and initializes.

Step 2: Run the Align build platform calibration

From the printer touchscreen, select Settings > Tools > Align build platform and follow the on-screen instructions.

Step 3: Re-activate biocompatible license (Form 4B customers only)

After the motherboard replacement, the biocompatible license will be temporarily disabled. Connect the printer to the internet to automatically refresh the license.

Step 4: Run a test print

Insert any missing consumables and upload and start a print. Check that the print starts normally and the parts print successfully. Contact Formlabs Support or your authorized reseller to share the results of the procedure.