Required Supplies:
Formlabs:
- Power supply
- 2.5 mm hex driver (included in the Form 4 tool caddy)
Third-party:
- Phillips screwdriver
- Nitrile gloves
The Form 4 power supply is located behind the touchscreen assembly and powers the printer. A broken or malfunctioning power supply prevents the printer from functioning.
Use this guide to replace the Form 4 power supply.

Required Supplies:
Formlabs:
Third-party:
Estimated time: 45 minutes
Preparing the workspace
Overview: Prepare the Form 4 and workspace for replacing the power supply.
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.
Notice:
Wear gloves and hold the resin tank by the tank grips on either side to avoid contamination or damage to the underside of the tank.
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
Warning:
Resin may cause skin irritation or an allergic skin reaction. Wear gloves when handling liquid resin or resin-coated surfaces. Wash skin with plenty of soap and water.
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.
Danger:
Fire hazard. IPA is flammable. Keep containers closed, and keep out of the reach of children.
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.
Danger:
Performing maintenance on the printer while it is plugged in increases the risk of electric shock. Never remove the printer panels while the printer is plugged in. Never reconnect the printer to power while the panels are uninstalled.
Removing the touchscreen assembly
Overview: Remove the touchscreen assembly from the printer to access the power supply.
Step 1: Remove the touchscreen assembly
To remove the touchscreen assembly, follow the instructions in the repair guide Replacing the Form 4 touchscreen assembly. Complete the steps in the section Removing the touchscreen assembly.
Removing the power supply
Overview: After removing the touchscreen assembly, remove the power supply.
Step 1: Open the plastic shroud

Release the five tabs holding the shroud closed. Unfold the top of the shroud.
Step 2: Unplug the output cable

Hold the connector by its plastic housing and gently squeeze the plastic tab to unplug the output cable from the power supply. Do not pull on the individual wires.
Step 3: Remove the input wire mounting screws

The input wires attach to the power supply with a ring terminal and screw. Using a Phillips screwdriver, remove each screw securing the ring terminal to the power supply. Set the screws aside. Do not remove the ring terminal from the input wire.
Step 4: Remove the power supply mounting screws

Use a 2.5 mm hex driver to remove the four hex screws that secure the power supply to the printer. Set the screws aside.
Step 5: Remove the power supply
Once all the cables are disconnected, gently lift the power supply from the printer. Set the power supply aside for disposal with electronic waste.
Installing the replacement power supply
Overview: Mount and connect the replacement power supply.
Step 1: Position the replacement power supply
Align the replacement power supply with the four screw holes on the printer frame. Take care to place the power supply in the correct orientation.
Step 2: Secure the power supply

Thread one hex screw into each screw hole. Using a 2.5 mm hex driver, hand-tighten the four hex screws to secure the power supply to the printer. Tighten the screws until snug.
Step 3: Connect the input wires
Match the correct input wire to the correct screw terminal. The black wire with the – label attaches to the upper screw terminal. The yellow wire with the + label attaches to the lower screw terminal. Thread a screw through the ring terminal into the screw terminal. Using a screwdriver, hand-tighten the two screws to secure the input cables to the power supply. Tighten the screws until snug.

Step 4: Connect the output cable
Connect the output cable to the power supply. The connector makes an audible and tactile click when secured.

Step 5: Close the plastic shroud
Fold the plastic shroud to cover the power supply. Reinsert the five tabs into the corresponding slots.

Reinstalling the touchscreen assembly
Overview: After replacing the power supply, reinstall the touchscreen assembly onto the printer.
Step 1: Reinstall the touchscreen assembly
To reinstall the touchscreen assembly, follow the instructions in the repair guide Replacing the Form 4 touchscreen assembly. Complete the steps in the section Installing the replacement touchscreen assembly.
Finalizing the repair
Overview: After replacing the power supply, 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: Run a test print
Insert any missing consumables and run a test 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.