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Power Tools · Troubleshooting

Power Tool Not Working: 6 Fixes for Battery, Motor, and Trigger Issues

Fix a power tool that won't start, starts and stops, or runs slowly. Covers battery connections, trigger switches, motor brushes, and warranty claims for DeWALT, Milwaukee, and Ryobi.

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How to fix it

Work through these in order, the most common causes come first.

  1. Fix 1: Charge the Battery Completely

    Before any other troubleshooting, charge the battery for the full recommended time. Partially charged batteries can provide enough power to light an indicator but not enough to run a motor under load. If the battery will not accept a charge (charger shows an error or doesn't respond), the battery protection circuit may have tripped due to deep discharge.

  2. Fix 2: Clean the Battery Terminals

    Battery connections degrade with dust, moisture, and oxidation on the contacts. Remove the battery from the tool and inspect both the battery contacts and the tool's battery slot contacts. Clean with a dry cloth or cotton swab, do not use liquid cleaners.

  3. Fix 3: Try a Different Battery

    If the battery appears charged and the contacts are clean, test with a different battery of the same voltage. This determines whether the issue is the battery or the tool. A tool that works with battery B but not battery A has a failing battery.

  4. Fix 4: Check the Safety Features

    Most cordless tools have a lock-off switch or lock button that prevents accidental starts. Confirm the lock-off is disengaged before the trigger. Grinders and circular saws often require holding a safety button simultaneously with the trigger, confirm you are operating it correctly.

  5. Fix 5: Inspect the Trigger Switch

    If the tool hums but doesn't spin, or starts intermittently, the trigger switch may have failed. Trigger switches are mechanical switches that wear out over thousands of actuations. Wiggling the trigger while pressing it can confirm this, if the tool starts and stops with slight trigger movement, the switch contacts are worn.

  6. Fix 6: Check Warranty and Service Options

    DeWALT, Milwaukee, and Ryobi all offer manufacturer warranties (typically 3 years for tools, 1-2 years for batteries) and factory service centers. If the tool is under warranty, contact the manufacturer before paying for repair. Milwaukee's ONE-KEY program allows some diagnostic information to be read from smart batteries.

Fix 1: Charge the Battery Completely

Before any other troubleshooting, charge the battery for the full recommended time.

Partially charged batteries can provide enough power to light an indicator but not enough to run a motor under load.

If the battery will not accept a charge (charger shows an error or doesn't respond), the battery protection circuit may have tripped due to deep discharge.

Leave the battery on the charger for 30-60 minutes, some chargers include a recovery mode for deeply discharged batteries.

Fix 2: Clean the Battery Terminals

Battery connections degrade with dust, moisture, and oxidation on the contacts.

Remove the battery from the tool and inspect both the battery contacts and the tool's battery slot contacts.

Clean with a dry cloth or cotton swab, do not use liquid cleaners.

On DeWALT and Milwaukee batteries, the gold-colored contacts should be clean and bright.

Green or white discoloration indicates oxidation.

Fix 3: Try a Different Battery

If the battery appears charged and the contacts are clean, test with a different battery of the same voltage.

This determines whether the issue is the battery or the tool.

A tool that works with battery B but not battery A has a failing battery.

A tool that fails with both batteries has a tool-side issue.

Fix 4: Check the Safety Features

Most cordless tools have a lock-off switch or lock button that prevents accidental starts.

Confirm the lock-off is disengaged before the trigger.

Grinders and circular saws often require holding a safety button simultaneously with the trigger, confirm you are operating it correctly.

Fix 5: Inspect the Trigger Switch

If the tool hums but doesn't spin, or starts intermittently, the trigger switch may have failed.

Trigger switches are mechanical switches that wear out over thousands of actuations.

Wiggling the trigger while pressing it can confirm this, if the tool starts and stops with slight trigger movement, the switch contacts are worn.

Trigger switch replacement is a common repair available at most service centers.

It is typically inexpensive compared to tool replacement.

Fix 6: Check Warranty and Service Options

DeWALT, Milwaukee, and Ryobi all offer manufacturer warranties (typically 3 years for tools, 1-2 years for batteries) and factory service centers.

If the tool is under warranty, contact the manufacturer before paying for repair.

Milwaukee's ONE-KEY program allows some diagnostic information to be read from smart batteries.

Ryobi's service is available through Home Depot stores for ONE+ products.

Power Tool Buying Guide - battery platform guide Best Power Tools for Home Improvement - replacement options

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Answers

Frequently asked questions

Why won't my cordless drill turn on?

The most common causes are: the battery is fully discharged (charge it fully with the manufacturer's charger before testing), the battery connection has debris or corrosion on the terminals, or the battery's internal protection circuit has tripped. Remove the battery, inspect the terminals, reinsert firmly, then try again. If the charger shows the battery is charged but the tool still won't run, try a different battery to isolate whether the issue is the battery or the tool.

Why does my power tool run slowly and feel weak?

Slow, weak performance usually means the battery is low or failing. A battery with degraded cells may show full charge on the indicator but deliver insufficient voltage under load. Test with a different battery, if the tool runs normally with a fresh battery, the original battery needs replacement. Brushed motor tools also slow down as brushes wear out after years of use.

Why does my power tool stop working mid-use?

Mid-use shutoff is typically thermal protection activating. When a motor or battery reaches a temperature threshold, the tool cuts power to prevent damage. Let the tool cool for 15-20 minutes before resuming. Frequent thermal shutoff during normal use indicates the tool is undersized for the task, use a higher-voltage or higher-capacity tool.

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