Checking the battery and the speed controller
Several standard faults can be identified that are inherent in cheap tools:
- The machine does not turn on;
- At work squeaks and whistles are audible;
- Speed and reverse control does not work;
- After the start button is switched off, the engine continues to operate;
- The tool turns on for a few seconds and jams;
- Strong chamfering of the chuck.
Do not turn on the screwdriver for the following reasons: the power button is broken, the brush brushes are worn out, or the anchor burns out, the battery is malfunctioning. The battery is checked by measuring the voltage at the terminals. The operating voltage is indicated on the housing and, if it is not in compliance with the test, it must be changed. Also, you should check the charger, the problem can be in it.
Note! The standard battery voltage is 12 or 18 volts.
Check the speed controller with a multimeter, ringing the chain. It should be noted that when the button is fully depressed, contact closure begins and the motor is directly connected to the motor. To the button are connected two wires from the battery, which are further connected to the engine. For continuity, the probe is attached to the input wire and alternately to the other. The button is pressed until it stops. The device indicates whether or not there is a contact. If there are no contacts, the button changes.
Replacing the
button You can repair the button yourself, but you need to know how to disassemble the screwdriver. It is necessary to understand that when the corps is opened, many details simply fall off. To prevent this disassembly of the screwdriver is done neatly, with a note of the location of all contacts and springs. If darkened contacts are found, they should be cleaned with sandpaper. After the assembly, repeated measurements are made and, if a contact appears, the button is put in place. Note that, if after replacement the engine has earned only when the button is fully pressed, and when the speed is not regulated smoothly, then the cause of failure in the adjustment circuit. In this case, you need to replace the entire button.
If there is no reverse, replace the reverse switch or repair it. To do this, the screwdriver is disassembled, and it is important to follow the rules described above. Contacts are checked and if they are deformed or burned, the reverse should be replaced. If the reverse button is assembled in the body of the start button, then the whole system changes entirely. If the engine continues to operate when the button is released, check the regulating transistor of the speed controller.
Tip! Before assembling the screwdriver, check all terminals and contacts, clean them, it will be useful for operating the tool.
Repairing the screwdriver with your own hands
If all of the above actions did not reveal the cause of the failure, then the serviceability of the engine brushes is checked. To do this, disconnect the engine from the button and check it with a multimedial. If there is no small resistance, the brushes are most likely worn out, but an anchor breakage is also possible. If the anchor burns out, the engine changes entirely, but if the cause is in the brushes, then the screwdriver and the engine are reworked. On some engines, you can make a brush change without having to dismantle the case, and some need to separate the back cover.
Note! With whistles and squeaks, you can drop oil on the bushings, but this is only a temporary measure that will solve the problem for a short time.
With long work with heavy loads, the reducer shaft may become curved, which is manifested in strong run-out during operation. In addition, the shaft bearing or support sleeve may wear out. If only the bushing or bearing is damaged, only these elements can be replaced, but when the shaft is bent, the entire system must be changed.