Makita GA4030K Troubleshooting

If the grinder is not turning on, the most common issue is that it is not receiving power. To fix this, make sure the tool is powered off and completely remove the plug from the wall outlet then reconnect it. If the device still won't power on, plug something else into the socket to make sure the fuse or the outlet has not blown.

A frayed power cable requires disassembly of the device body and then replacement, while an internally disconnected power cable requires disassembly of the tool body and then reconnection of a few screws to reattach the cable to the power sink. See the electrical cord replacement guide for further instructions.

This is similar to a frayed or internally disconnected power cable. A broken or internally disconnected power switch requires disassembly of the device's body for replacement and reconnection. See the switch replacement guide for further instructions.

The most likely cause of sparks and/or smoke is disconnection or wearing down of the carbon brushes. The carbon brushes are two pieces of an electric motor which transmit current to the rotating armature via the commutator. When worn or broken carbon brushes interact with the communicator abnormally, they can produces sparks and/or smoke. See the carbon brush replacement guide for further instructions.

Often sparks and/or smoke can be caused by a broken armature. The communicator (which is part of the armature) may have been damaged or broken by the carbon brushes. Overworking the tool may also cause the armature to break by burning out the windings (the copper wires in the armature). In either case, see the armature removal guide and check for any visible damage.

Apply less pressure to the angle grinder when grinding a surface or after working a hefty job. It is recommended to let the grinder spin freely for a couple of seconds to allow the tool to cool down. Give the angle grinder some time to cool down after any job and refrain from continued use over long periods of time.

Because an angle grinder is a multipurpose tool, it comes with multiple wheels and disks. Make sure the correct size and type of disk is being used for the task at hand. After checking the disk, look for signs of the disk deterioration such as dull blades, chipped edges, cracks, or uneven wear.

If the angle grinder is not spinning at a constant speed or is slower than normal, the carbon brushes may be worn down. The carbon brushes are two pieces of an electric motor that transmit current to the rotating armature via the commutator. Worn carbon brushes can decrease the overall performance of the motor. See the carbon brush replacement guide for further instructions.

Turn device off completely before unplugging it from the extension cord. Try plugging the device directly into a wall outlet to see if the performance and speed increase.

An excessive amount of heat may be caused by a lack of grease in the wheel bearing. Grease is a lubricant which helps to decrease the amount of internal friction within the device. See the grease replacement guide for further instructions.

There may be dirt, sand, or metal bits in the grease that would create friction thus causing heat. This can be fixed by cleaning the inside of the device. See guides for replacing the armature and replacing the grease and then blow with compressed air.