my makita xfd131 drill is fully charged but it just clicks once and won’t spin when i pull the trigger

Diagnosis

The single "click" you are hearing is the sound of the electronic brake and the motor controller's safety circuit engaging and immediately disengaging. On the Makita XFD131, which utilizes a brushless motor, the trigger is not a simple on/off switch but a variable speed potentiometer that sends a signal to the electronic control board. When the board detects an inconsistent signal, a short circuit, or an open loop in the trigger assembly, it kills power to the motor instantly to prevent a catastrophic failure of the MOSFETs on the control board. This typically happens because of carbon dust buildup or metallic shavings from drilling that have migrated into the trigger housing, causing a "bridge" between contacts. Alternatively, the internal spring-loaded contact in the trigger assembly has worn down or shifted, meaning the board sees a "phantom" trigger pull or an incomplete circuit. You can confirm this is a trigger/board issue rather than a battery issue by swapping in a different 18V LXT battery; if the single click persists across multiple fully charged packs, the fault lies within the tool's internal switching logic.

How to Fix It

Since the XFD131 is a sealed unit, you should first attempt a non-invasive chemical cleaning before dismantling the housing.

1. Remove the 18V LXT battery pack immediately to prevent any accidental shorts during the cleaning process.
2. Position the drill so the trigger assembly is facing slightly downward. Use a high-pressure can of CRC QD Electronic Cleaner or a similar non-residue contact cleaner.
3. Insert the straw nozzle deep into the gap between the trigger and the plastic housing. Spray in short, 2-second bursts while simultaneously pulling and releasing the trigger rapidly 20 to 30 times. This mechanical action helps the solvent break up carbonized debris and grit.
4. Rotate the tool's torque clutch ring through all settings (1 through 20) and flip the forward/reverse switch back and forth several times. Debris in the directional switch can also cause the controller to "click" and shut down.
5. Wait exactly 15 minutes for the solvent to fully evaporate. Using the tool while the cleaner is still wet can cause a short that permanently fries the brushless control board.
6. Reinsert the battery and test the trigger with a light, gradual squeeze rather than a full pull.

If That Didn't Work

• Replace the Trigger Switch Assembly: If cleaning fails, the internal potentiometer has likely failed. You will need to remove the outer casing screws (typically T10 Torx) and replace the trigger assembly. Ensure you purchase the specific brushless-compatible switch for the XFD131, as the brushed motor switches are not compatible and will cause the tool to smoke.
• Inspect the Directional Switch: The forward/reverse slider is a common failure point. If the slider is stuck in a "middle" position, the board will not engage the motor. Use a needle to clear any packed sawdust or drywall mud from the edges of the slider and toggle it firmly.
• Check for Battery Terminal Oxidation: Inspect the copper contact rails inside the battery slot. If there is a thin layer of oxidation (dull grey film), the board may detect a voltage drop the moment the motor tries to draw current, triggering the safety click. Clean these contacts using a cotton swab dipped in 90% isopropyl alcohol.
• Test the Control Board: If the trigger is replaced and the click persists, the brushless controller board has likely suffered a capacitor failure. Since these boards are potted in resin, they cannot be repaired and the entire electronic assembly must be replaced.

Heads Up

• Avoid Lubricants: Never use WD-40 or graphite lubricants inside the trigger housing. These attract metallic dust which creates a conductive sludge, leading to permanent short circuits in the brushless controller.
• Voltage Warning: Always remove the battery before opening the casing. Even when "off," the capacitors on the brushless board can hold a charge that may spark if touched by a metal tool.
• Dust Management: If you frequently drill into masonry or drywall, use compressed air to blow out the trigger and vent areas once a month to prevent the buildup that causes this specific failure.
• Battery Compatibility: Ensure you are using genuine Makita LXT batteries. Third-party "knock-off" batteries often have inconsistent voltage ripples that can confuse the XFD131's sensitive electronic protection circuit, resulting in the single-click shutdown.