What could be wrong with your starter if the car is not starting up?

1. Weak or dead battery: If the battery is not providing enough power, the starter will not be able to turn the engine over. Check the battery terminals for corrosion, and make sure the battery is properly connected. If the battery is old, it may need to be replaced.

2. Bad starter motor: If the starter motor is faulty, it will not be able to turn the engine over. This can be caused by a number of things, such as worn brushes, a bad solenoid, or a burnt-out armature.

3. Faulty ignition switch: If the ignition switch is faulty, it will not send the power to the starter motor. This can be caused by a number of things, such as a worn key cylinder or a bad electrical connection.

4. Damaged flywheel or ring gear: If the flywheel or ring gear is damaged, it will not be able to mesh with the starter motor. This can be caused by a number of things, such as an engine that has been dropped or a broken flex plate.

5. Bad electrical connections: If there is a bad electrical connection between the starter motor, the battery, or the ignition switch, the starter motor will not be able to receive the power it needs. Check the connections for corrosion and make sure they are tight.