DIY Grass Trimmer Repair, Frequent Causes Of Breakdowns.

The use of various electrical devices greatly simplifies the implementation of many types of work, but unfortunately, all complex products sooner or later break. Electric trimmer failure will lead not only to the inability to carry out work in the garden but also to significant financial expenses for repairs. Significantly save money and improve their knowledge in the device of this technology is possible if repairs the trimmer to do it yourself. Before you start this type of work, you should carefully examine the principle of operation of this type of household appliances.

Electric trimmer: device and principle of operation

Electric trimmer consists of:

  • Enclosures with electric motor.
  • Removable rod.
  • Trim coil with protective cover.
  • Gluing for shoulder strap.

A power cable with a plug is connected to the trimmer body, through which electrical current is transmitted. In the cavity of the split rod is a flexible shaft, through which the transmission of torque to the trim coil. The device is turned on by pressing the button located on the device handle.
This trimmer design is the most common, but if you wish, you can find battery-powered products, as well as with the lower location of the electric motor.

Do-it-yourself grass trimmer repair: common causes of breakdowns.

Trimmer can fail when working under conditions of high loads. Such a situation may occur when the treated area is covered with tall grass.
When working in such areas, the engine may fail, bearings may break, and the electric loader coil may collapse. When working in rainy weather or conditions of severe fog, the trimmer may “burn” as a result of the formation of a short circuit.
Damage to this electrical device may occur as a result of frequent use. If the household appliance is to be used in this mode, then after operating a certain number of hours, it will be necessary to carry out the necessary repair and preventive adjustment of many parts of the electrical appliance.

Repair start button.

If the electric car does not show signs of life, then there may have been a break in the electric cable inside the body handle, or the electric motor start button is faulty.
To make diagnostics, electricians will need to disassemble the handle of the appliance.

Works are performed in the following sequence:

  • Removes the control knob from the frame electrocutes.
  • The handle is disassembled.

When access to the inside of the electric scythes is provided, the resistance button of the electric trimmer is measured using a multimeter. If there is no resistance after pressing, then this.
The item is subject to mandatory replacement. It is also necessary to check the connection points of the power cable with the internal electrician located in the handle.
Device. Contacts should be checked for “breakage” with a multimeter. Often such a malfunction can be identified “by eye”. After detecting a contact break, it is sufficient to solder the damaged place to restore the work of the electric trimmer.
In the absence of a multimeter, diagnostic work can be performed with an indicator screwdriver. For this purpose, you must plug in the power supply and with the help of this diagnostic tool.
Find the “phase wire” and thus check the presence of electric current before and after the power button. If the phase current is detected in a different electronic circuit, it is sufficient to install an electrical plug in the outlet on the contrary so that that accurate diagnostics can be performed.
Trimmer malfunction. The second diagnostic option should be carried out with great caution since there is a danger of electric shock while checking the integrity of the wiring.

Motor check.

If the instrument’s power button and internal wiring areas are intact, then you should proceed to check the electric motor. For this purpose, it is necessary to remove the housing cover, after unscrewing a few screws with a screwdriver.
The first thing you need to do after access to the electric motor is to check the functionality of the brush unit. If the brushes are worn out beyond the maximum permissible value, the electric motor may completely stop or work unstably. In the case when the brushes and the collector are in perfect order, one should proceed to “ringing” the motor winding. To eliminate the likelihood of breakage in both circuits should be carried out alternately checking the stator and rotor of the engine.

To perform this operation, you must:

  • Remove the engine from the electric scythes.
  • Turn multimeter into resistance measurement mode and check all collector plates for open circuit. When checking also there should be no significant deviations in the testimony of the diagnostic device.
  • Check for a breakdown of the rotor winding to ground. For this purpose, one multimeter probe should be connected to the “mass” of the rotor, and the other to any collector plate. The multimeter must be set to measure resistance to more than 1 MΩ. The resistance of a healthy motor between the winding and the “mass” must be huge.
  • Measure the resistance value of the stator winding. If the resistance is absent, then we can state in this case its failure.
  • If the stator wiring is in perfect order, then a possible breakdown of it on the case is checked, in the same way as in the diagnosis of the stator.

When checking in this way, it is possible in 90% of cases to establish the cause of a motor failure. To check for winding closure, which can manifest itself only in the process of engine operation, this will not work, but you can diagnose such a fault by indirect signs, which are manifested in a decrease in the power of the electric motor and its overheating. If the electric motor is equipped with a thermal relay, then such an electric boom, during the inter-turn circuit, will work for a short time, after which the trimmer will automatically turn off. In some cases, the thermal relay may cause a malfunction of the trimmer motor, therefore, in a set of test events should be enabled “ringing” of the thermostat with a multimeter or tester.
It is very simple to do this: in good condition on a cold engine, the thermal relay passes an electric current, a faulty electrical circuit will open.
The performance problems of electric scissors connected with the break of the wires are easily eliminated by soldering the contacts, but if the motor “burned out”, then you will need to perform a complex rewinding process, which can perform only a qualified technician. In many cases, it is much easier and cheaper to purchase a new engine and install it in the place of the burned one. This work can be done independently.
If the trimmer electrician is in good condition, then you should pay attention to other types of malfunctions that may occur during operation of the electric scythes.

Mechanical Malfunction Trimmer.

If the electric motor of the device is turned on, but the rotation of the reel with the fishing line does not occur, the causes of such a malfunction may be a break in the flexible shaft of the transmitting torque. This problem is especially often manifested in the improper care of electrical appliances. For example, if there is no lubrication inside the boom, the electric cable ties will be subject to excessive friction, and for a short time, this part will break down. For replacement, it is enough to disconnect the upper part of the electric sockets in which the electric motor is located, after which it will be possible to remove the flexible shaft from the rod.
If there are difficulties with the extraction of the second part of the cable remaining in the inside of the cavity, the lower part of the spit is disconnected from the reel and shaft. The assembly mechanism is in reverse order.
Before installation, the flexible shaft must be carefully lubricated with grease to reduce the likelihood of this component re-breaking.
The rupture of a flexible shaft can occur only in models of an electric trimmer with a top engine.
Electric mowers with a lower engine position do not have a flexible shaft, but malfunctions of such devices can manifest themselves in the form of destruction of the main shaft bearing and electric mows on which the reel with fishing line is installed.
To fix such a malfunction is very easy to replace the failed bearing with a new part.


With frequent use and inadequate care of the electric mowers, the listed malfunctions can appear with great regularity. To minimize the chance of breakage, it is enough not to overload the device, lubricate moving parts in time and not work at high humidity. Despite some limitations when working with this device with an electric trimmer, unlike petrol trimmers, there can be no malfunctions in the ignition unit. And such a fault as: “the trimmer motor immediately stalls” in principle can not be. The motor of an electrical device cannot stall since it is not required to start. To start, press the power button, so many gardeners choose, for the care of the surrounding area, electric trimmers.