my craftsman v20 drill just clicks but the chuck doesn't spin at all, battery is charged, what's wrong?

Diagnosis

The "clicking" sound you hear when pulling the trigger on your Craftsman V20 CMCD700C1 is the sound of the electronic variable speed switch engaging the relay, but the electrical circuit is failing to complete the loop to the motor. Since the battery is confirmed charged, the issue is almost always a break in the electrical path between the trigger and the armature, or a mechanical failure in the planetary gear set. If the click is accompanied by a slight "thump" but no rotation, the motor is likely trying to engage but is stalled by a seized gear or a sheared keyway. However, if it is a crisp electronic click with zero motor hum, the root cause is typically worn-out carbon brushes or a failed trigger switch. In the V20 series, carbon dust can accumulate inside the switch housing, creating an insulating layer that prevents the contact points from meeting, even though the mechanical action of the trigger is still functioning.

How to Fix It

To resolve a power delivery failure in the CMCD700C1, you must perform a deep clean and a brush inspection. You will need a T15 Torx driver and a can of electronic contact cleaner.

1. Remove the battery and use the T15 Torx driver to remove all housing screws. Note that some screws may be hidden under stickers or located in the grip area.
2. Carefully split the clamshell housing. Be mindful of the trigger assembly; do not pull the two halves apart violently, as there are thin wires connecting the trigger to the motor.
3. Locate the motor brushes. These are the two small carbon blocks held against the commutator by springs. Use a small flat-head screwdriver to gently slide the brushes out of their holders.
4. Inspect the length of the carbon. If the brush is worn down to less than 5mm (approx 1/4 inch) or if the carbon is pitted and uneven, replace them with a compatible V20 brush set.
5. While the housing is open, spray a burst of electronic contact cleaner directly into the trigger switch mechanism. Actuate the trigger 20-30 times to work the cleaner into the contacts and clear out any conductive carbon dust.
6. Reassemble the housing, ensuring no wires are pinched between the plastic shells, and tighten the T15 screws firmly but not over-tightly to avoid stripping the plastic threads.

If That Didn't Work

• Test the Trigger Switch: Use a multimeter set to Continuity mode. Probe the leads coming out of the trigger switch while pulling the trigger. If the meter does not beep or show a closed circuit when the trigger is fully depressed, the switch has failed internally and the entire trigger assembly must be replaced.
• Check the Commutator: Inspect the copper segments of the motor armature. If they are blackened or charred, the motor has suffered a "flashover." Use a fine-grit sandpaper (600 grit) to lightly clean the copper bars until they are bright again, then blow out the debris with compressed air.
• Inspect the Planetary Gears: If the motor spins but the chuck doesn't, the problem is mechanical. Open the gear housing at the front of the drill. Look for sheared teeth on the planetary gears or a stripped output shaft. If the gears are stripped, the gear head assembly needs to be replaced as individual gears are rarely sold for this model.
• Verify Battery Terminal Tension: Check the metal contact tabs where the battery slides into the drill. If they are recessed or bent, they may be making enough contact to trigger the electronics but not enough to carry the high current required to spin the motor. Gently pry them forward with a small pick to ensure a tight fit against the battery terminals.

Heads Up

• Avoid using WD-40 inside the trigger switch; it leaves a residue that attracts carbon dust and will eventually cause the switch to fail again. Use only non-residue electronic contact cleaner.
• When replacing brushes, always ensure the springs are seated correctly. A misaligned spring can cause the brush to jam, which will arc and burn out the motor commutator in seconds.
• If you notice a burning smell during the "clicking" phase, immediately remove the battery. This indicates a short circuit in the trigger wiring that could permanently damage the battery cells.
• Keep the ventilation slots of the motor clear. The V20 series relies on a small internal fan; if these slots are clogged with drywall dust or sawdust, the motor will overheat and wear the brushes down prematurely.