Quick answer
- Most of the time it's the battery, not the driver. Drop in a different charged M18 pack before you do anything else.
- Blow out and clean the battery contacts and the rails inside the tool. Sawdust and grit there fake a dead motor.
- Check the forward/reverse button above the trigger; see your operator's manual for how it works on your model.
- If a hot tool just quit under load, set it down and let the tool and pack cool.
What the symptom is telling you
"Not working" shows up a few ways on a Milwaukee impact driver, and each one points somewhere different. Dead silence with a charged battery can mean a contact or trigger problem. A tool that runs strong then fades points at a tired or hot pack. Sort out which one you've got and you stop chasing the wrong part.
Kill one myth first. The M18 Fuel drivers (the 2953-20 and its siblings) are brushless. There are no carbon brushes inside to wear out or swap, so any guide telling you to replace the brushes is written for an older brushed tool, not this one.
Start with the battery
This is the fix more often than not, so do it properly rather than guessing.
- Swap in a known-good pack. Put a different fully charged M18 battery in the tool. If it runs, the original pack is your problem and the driver is fine. Remember the platforms don't cross: an M12 battery won't fit an M18 tool, and the reverse is true too.
- Read the fuel gauge. Press the button on the pack. Dim lights, or a pack that won't show full after a long sit on the charger, means the cells are worn down.
- Mind the temperature. A charger won't charge a pack that's too cold or too hot; check your charger's manual for its limits. That's a normal safety interlock, not a defect. A pack left in a cold truck overnight may just need to reach room temperature before it'll take a charge or run.
- Seat it all the way. Push until it clicks hard. A battery that's a touch loose can read as stone dead.
Then clean the contacts
If a fresh battery doesn't wake it up, look at where the pack meets the tool. Pop the battery and check the terminals on both the pack and the rails inside the driver. Drywall dust, grit, and a little corrosion build up in there and break the circuit. Hit it with compressed air and gently clean the contacts. Don't pry or bend the terminals; bent rails cause more dead tools than dirty ones.
The button people forget
Check the forward/reverse button above the trigger; see your operator's manual for how it works on your model. Make sure it is fully set to forward or reverse and pull the trigger again. It feels too obvious to bother with, and it's caught plenty of people who were a phone call away from a warranty claim on a perfectly good tool.
A tool that only runs flat-out, cuts when you ease off, or fires intermittently may have a worn trigger switch rather than a bad motor, which is a service item.
When it quit mid-job
If the driver died in the middle of heavy work and the housing feels hot, set it down and let the tool and pack cool before you judge them. A hot pack also won't charge until it cools.
When it's genuinely dead
If a known-good battery, clean contacts, and the forward/reverse button confirmed, still get you nothing, the failure is inside the tool, usually the switch or the electronic control module. Milwaukee's default tool warranty is five years, so check your purchase date and Milwaukee's warranty page before you open anything up. A tool still under warranty often gets repaired or swapped at a service center for nothing, which beats buying parts and fighting the housing yourself.