The Form 4L touchscreen is the primary means of interacting with and controlling the printer. A broken or malfunctioning touchscreen may prevent the printer from being used normally.

Use this guide to replace the Form 4L touchscreen assembly.

Estimated time: 30 minutes

Overview: Prepare the Form 4L and a dust-free workspace for replacing the touchscreen assembly.

Step 1: Remove the build platform

Remove the build platform first to avoid dripping resin onto the optical surfaces.

Step 2: Remove the resin cartridges

Remove the resin cartridges and close the vent caps 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.

Step 5: Clean the printer

Open the printer cover and clean any resin pooled on and around the LPU with paper towels. Dampen the paper towels 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.

Overview: Remove the side panels to access the touchscreen assembly.

Step 1: Remove the mesh filter

Remove the mesh filter from the right side of the printer. Set the filter aside.

Step 2: Remove the lower right panel screws

Use a 2.5 mm hex driver to remove the four screws securing the lower right panel to the printer. Set the right panel and the screws aside.

Step 3: Remove the lower left panel screws

Use a 2.5 mm hex driver to remove the four screws securing the lower left panel to the printer. Set the left panel and the screws aside.

Overview: Remove the front panel to access the touchscreen assembly.

Step 1: Remove the left front panel retention screws

Use a 2.5 mm hex driver to remove the three screws securing the left side of the front panel to the printer. Set the screws aside.

Step 2: Remove the right front panel retention screws

• Use a 2.5 mm hex driver to remove the countersunk screw securing the upper part of the front panel to the printer.
• Use a 3 mm hex driver to remove the screw securing the lower part of the front panel to the printer.

Set the screws aside.

Step 3: Position the printer

With a second person, position the Form 4L near the front edge of the workspace to access the bottom screws.

Step 4: Remove the bottom front panel retention screws

Use a 1.5 mm hex driver to remove the two screws securing the front panel to the bottom of the printer.

Step 5: Reposition the printer

With a second person, position the Form 4L so that there is at least 6 inches (150 mm) of workspace in front of the printer.

Step 6: Remove the front panel

Grip the front panel by its bottom corners. Carefully pull the front panel towards you. Rotate the front panel until its back surface is visible. Do not pull away from the printer until the touchscreen ribbon cable is disconnected. Lay the front panel with the glass face down on a clean, level surface.

Step 7: Disconnect the touchscreen ribbon cable

The touchscreen ribbon cable connects the touchscreen assembly to the motherboard. The motherboard is located on the left side of the printer.

• Rotate the black plastic tab on the connector away from the motherboard to unlatch the touchscreen ribbon cable.
• Rotate the black plastic tab on the connector away from the touchscreen assembly to unlatch the other end of the touchscreen ribbon cable.

Once the black tabs are properly released, the cable slides out of the connectors with minimal force.

Step 8: Release the ribbon cable clamps

Use a 2.5 mm hex driver to loosen the four screws securing the ribbon cable clamps to the front panel. Do not fully remove the screws. Once the ribbon cable clamps are properly loosened, slide the touchscreen ribbon cable out of the clamps and set it aside for disposal with electronic waste.

Step 9: Remove the touchscreen assmbly nuts

Use a 7 mm nut driver to remove the five nuts securing the touchscreen assembly to the front panel. Set the nuts aside.

Step 10: Remove the touchscreen assembly

Lift the touchscreen assembly from the front panel and set it aside for disposal with electronic waste.

OVERVIEW: Install the replacement touchscreen assembly.

Step 1: Position the replacement touchscreen assembly for installation

Position the replacement touchscreen assembly on the front panel. The touchscreen assembly will only fit the front panel in the correct orientation. Make sure that the front panel bolts align with the screw holes on the touchscreen assembly.

Step 2: Secure the replacement touchscreen assembly

Place a nut on each of the five bolts on the front panel. Use a 7 mm nut driver to tighten the five nuts securing the touchscreen assembly to the front panel.

Step 3: Route the replacement touchscreen ribbon cable

Route the replacement ribbon cable through the clamps and behind the other cables on the left side of the printer. Do not pull or bend the cable. Do not tighten the ribbon cable clamp screws.

Step 4: Connect the touchscreen ribbon cable to the touchscreen assembly

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

Step 5: Connect the touchscreen ribbon cable to the motherboard

Slide the other end of the ribbon cable into the connector on the motherboard. Make sure the cable is inserted evenly. The blue mark should face upward.

Step 6: Secure the ribbon cable

Flip down the black tabs on the connectors to secure the cable to the touchscreen assembly and motherboard. Take care not to pull on the cable during installation.

Step 7: Secure the ribbon cable clamps

Use a 2.5 mm hex driver to tighten the clamps. Ensure there is slack in the touchscreen ribbon cable on both sides. Do not overtighten.

Step 8: Position the front panel for installation

Position the front panel at an angle to 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 new touchscreen ribbon cable.

Step 9: Mount the front panel

Mount the front panel onto the printer frame. Ensure the two tabs on the bottom of the front panel slide the corresponding slots in the printer frame.

Step 10: Secure the right front panel retention screws

• Thread the 2.5 mm countersunk screw into the upper screw hole in the printer frame. Using a 2.5 mm hex driver, tighten the screw until finger tight.
• Thread the 3 mm screw into the lower screw hole in the printer frame. Using a 3 mm hex driver, tighten the screw until finger tight.

Step 11: Secure the left front panel retention screws

Thread one screw into each of the three screw holes in the printer frame. Using a 3 mm hex driver, tighten the screws until finger tight.

Step 12: Position the printer

With a second person, position the Form 4L near the front edge of the workspace to access the bottom screws.

Step 13: Secure the bottom front panel retention screws

Using a 1.5 mm hex driver, secure the bottom front panel retention screws to the printer. Tighten the screws until finger tight.

Overview: After performing any other maintenance procedures, reinstall and secure the side panels.

Step 1: Align the left side panel with the printer

Lift the left side panel and align it with the left side of the printer.

Step 2: Secure the left side panel

Thread the four 2.5 mm screws into the screw holes on the left side of the printer. Using a 2.5 mm hex driver, tighten the screws until snug.

Step, 3: Align the right side panel with the printer

Lift the right side panel and align it with the right side of the printer.

Step 4: Secure the right side panel

Thread the four 2.5 mm screws into the screw holes on the right side of the printer. Using a 2.5 mm hex driver, tighten the screws until snug.

Step 5: Reattach the mesh filter

Vacuum the mesh filter until it is free from debris. If the mesh filter cannot be cleaned, replace it. Reattach the mesh filter to the printer, ensuring that it is aligned with the air intake vents.

OVERVIEW: After replacing the touchscreen assembly, power on the printer and perform final checks.

Step 1: Power on the printer

Connect the power cable to the printer and the power supply. The printer initializes.

Step 2: Test the touchscreen

The touchscreen should respond to touch inputs if the repair was successful. Test a variety of inputs, such as viewing the printer’s settings or exploring past prints via the print queue. Contact Formlabs Support or your authorized reseller to share the results of the procedure.