Cordless Drill: Won't Turn On

A battery is a container consisting of one (or more) cells, which chemical energy is converted into electricity and used as a power source. If the battery will not hold a charge, then it will need to be replaced. Batteries have a life cycle, which all vary, depending on the materials used to make them. Eventually, they will reach their charging limit. The battery near the end of its life will not hold as much power and will require to be charged more frequently, eventually dying out. When this occurs, purchase a new battery.

The brushes provide the electrical current to the armature by riding on the commutator. If these brushes become damaged in any way, it can impact their ability to provide the electrical current.
To check the condition and replace these brushes, if needed, start by removing the battery. Remove the screws on the end cap and pull off the drill. Locate the spade connectors and remove them with pliers. Insert a small screwdriver in the access hole, close to the center of the housing, and gently pry out the brush.
On some drills, you will have to remove the case on the housing and remove the two screws securing the transmission to the drill on the same side the cover is located on. Then, remove the cover. One brush will be in the cover and the other under the motor.
Remove the hold-down bracket on the motor to access the second brush. Check for wear, weak springs, heavy dirt build-up and replace as needed.
Insert back in the housing and then reinstall the spade connectors. Tighten the motor back in the housing with the hold-down bracket. Reinstall the cover on the housing and reattach the two screws securing the transmission to the drill. Put the end cap back on and test the drill.

The charger charges the battery. When you place the battery into the charger, the light should indicate that it is charging. If it is not charging, then check the connectors for corrosions or any other dirt build up. If you notice any corrosion on the contacts, then you will need to clean the contacts. Unplug the charger before cleaning. Use a small screwdriver to gently scrape any corrosion off the connectors – or, anything else that may work. Recheck to see if the battery will now charge. If the problem persists, replace the charger.

An electric motor is an electrical machine that converts electrical energy into mechanical energy. To replace the motor, remove the two screws holding the transmission to the motor on the side of the transmission where all of the housing screws are facing upwards on the case, that secure the case to the housing. Next, remove the screws securing the case to the housing and remove the case. Remove the other two screws on the transmission that secure it to the motor. Remove the screws securing the hold-down brackets on the motor and then the motor and transmission assembly. The motor should just twist away from the transmission.
Twist the new motor onto the transmission – it may take a few tries as you need the gears to mesh up. Reattach the transmission to the motor and secure the two screws. Reinstall back in the housing. Put the hold-down brackets on the motor, securing it to the housing. Reinstall the second brush holder into the drill. Put the case back on the housing and reinstall the last two screws, securing the transmission to the motor.

The switch turns the power on and off on the drill. Make sure the battery is good and that the drill will not work in both forward and reverse positions, before replacing the switch. To replace the switch, first removed the end cap on the drill. Next, remove the two screws holding the transmission to the motor on the side of the transmission where all of the housing screws are facing upwards on the case, that secures the case to the housing. Next, remove the screws securing the two halves of the case together and separate the halves. Remove the other two screws on the transmission that secure it to the motor. Remove the screws securing the hold-down brackets on the motor and then the motor and transmission assembly. Remove each wire from the brush holder and do not mix up where they attach.
Take the switch off of the drill. Install the new switch in the housing and connect the wires in the slots, inside the housing. Reattach the wires to the correct brushes and insert the brushes back into the drill housing. Reinstall the motor and transmission assembly back into the drill housing. Reinstall the hold-down brackets and secure them with the screws. Reinstall the two screws securing the transmission to the drill case. Reinstall the second brush holder into the drill. Reinstall the case back into the housing followed by the two other screws securing the transmission to the motor.

Holders provide stable support of the brush, in the proper position in relation to the contact surface of the commutator. If the holder has become damaged and can no longer support the brush properly, it will need to be replaced. On some models, you can just remove the end cap to access the holders. Remove the holders and inspect for breakage and replace, if needed. For other drill models, you will need to remove the cover and the two transmission screws that are located on the same side as the cover. Pull the cover off. One brush holder is located in the cover and the other is found under the motor in the housing. Remove the motor hold-down bracket and lift the motor up to access. Inspect the holders and replace as necessary. Reinstall the holder in the housing and reinstall the motor, securing it with the hold-down bracket. Reattach the cover and tight. Reinstall the two transmission screws and reattach the end cap.