1. Power switch

　　The power switch of mosquito swatter is usually 6x6mm touch type micro key switch, which works under the condition of 120-200ma. Due to frequent operation to turn on and off the power supply, it is easy to damage. There are two types of damage:

　　(1) the contact is in poor oxidation contact, the indicator light is not on, and the mosquito swatter does not work.

　　(2) the reed is tired, the contact is stuck, and the indicator light is always on. Once the battery is installed, the mosquito swatter will work. The micro switch is small in size and troublesome in maintenance. It is usually replaced with a new one.

　　2. Step up transformer

　　Most of the damage forms of step-up transformer are secondary L3 turn to turn insulation breakdown, which shows that t cannot hear the "squeak" audio sound at the moment of power on, and there is no spark when touching the metal net. Measure the normal resistance value of both ends of L3 with the multimeter RXL, which is about 80 Ω. In case of open circuit or lower than the normal resistance value, it is deemed as damage. Another inspection method is to use a cutter to cut and lay copper foil on the secondary part of the transformer, and use a multimeter AC block to measure both ends of L3. The normal AC voltage reading is about 230V. If there is no voltage, it will be regarded as damage.

　　Open the pins of T, remove the transformer, pull out the black core and remove the external insulation. Remove the secondary enameled wire and record the turns, then rewind it with φ 0.08 ~ φ 0.12mmqz high-strength enameled wire. The enameled wire can be removed from the broken small ceiling fan or the broken small power transformer.

　　3. Oscillating tube

　　The resistance value of the secondary winding L3 of the transformer T is 80 Ω normal. If there is no 230V voltage at both ends of the L3, most of the fault is that the oscillating tube VT is damaged. Weld down the oscillating tube, and use the multimeter to detect and judge whether it is good or not. Replace it with the prototype No. s8050, or replace it with NPN triode such as d467, d468, 9013, etc.

　　4. Double voltage rectifier element

　　The breakdown, short circuit or open circuit of any one of the capacitor C1-C5 and diode vdl-vd5 of the voltage doubling rectifier element will cause no high voltage or high voltage shortage. The main reason is that the voltage resistance of the components is insufficient or the electrical performance used is poor. Use a multimeter to test one by one. Usually, C1 or VDL breakdown is more common. After the capacitor is damaged, replace it with 333j / 630V polyester capacitor; after the diode is damaged, replace it with ln4007 silicon rectifier tube.

　　5. Battery box and battery

　　Most of the failures of the battery box are battery leakage, which causes corrosion, oxidation and poor contact of the positive copper plate or negative spring, resulting in the failure of the mosquito swatter to work, and the rust can be completely scraped off with a knife. If the mosquito swatter is not used for a long time, the best way to prevent electrode corrosion and oxidation is to unload the battery.

　　The battery consumes electricity for a long time. If the voltage of each battery is lower than 1V (the brightness of the indicator LED is dark), the high voltage will be insufficient and the mosquito killing effect will be poor. Replace the battery.

　　6. High voltage metal mesh

　　Long term use or collision with objects will cause deformation and looseness of high-voltage wire mesh, which may cause short circuit and spark. The user thought he had hit the mosquito, but he didn't know it had broken down. If the contact short circuit will cause damage to the rectifier elements and transformer, it is necessary to check and maintain it frequently. If the deformed steel wire is found, it needs to be reshaped. If it is loose, it needs to be reset and then stuck with yellow glue.

　　7. Indicator light VDL is not on

　　Under the condition of ensuring the normal power supply of battery g, the fault is caused by the poor internal contact of button switch sb. Sb is a 6 mm × 6 mm vertical micro touch switch, which is frequently switched under the working current of 120 mA. It is very easy to cause the internal contact oxidation open circuit, and the fault can be eliminated by replacing it with a new one.

　　8. VD1 is on, but no high pressure is generated.

　　At this time, the audio "squeak" generated by transformer T at the moment of power on is not heard. Sound, indicating that the oscillating circuit is not working. Most of the causes of the fault are VT damage. Replace the new pipe 2n5609 or d467 to eliminate the fault. If there is no such tube on hand, 8050 and 9013 NPN type triode can also be used instead, with good effect. If the VT is not damaged and obviously hot after power on, it means that the internal coil of transformer T (especially high-voltage coil L3) is broken down, and it must be rewound with enameled wire of the same specification. Generally, this kind of fault is rare.

　　9. Insufficient high voltage

　　Most of the reasons are that there is an open circuit of capacitance or the capacity is smaller in C1-C3, or one of the diodes vd2-vd4 is damaged, so it is necessary to detect and replace it with a new one; in addition, the insufficient g voltage of the battery (the brightness of VDL is obviously reduced) will also cause the insufficient high voltage, so long as the battery is replaced, the fault can be eliminated. Mosquito swatter is the principle of inverter. It converts direct current into alternating current, and then generates more than one thousand volts of direct voltage through double voltage. It uses high voltage to shock mosquitoes.

　　Manufacturer of mosquito lamp: http://www.gdfeilida.com