Inside the Mosquito killer

Nowadays, people widely uses mosquito killer bats because of their easy usage. The product is imported from China for very cheap price. There's some electronics inside it. If you understand the working principle of that circuit and if you are an owner of soldering iron, you can easily troubleshoot the problems and can use the product for a long time.
The power source of old products was dry cells, while now it is rechargable battery of 2.4V. There is bridge rectifier and a capacitor is used to get enough power to charge the battery. Transistor become ON, when switch is closed and the sudden change in current in the primary coil in the transformer forms a higher voltage. The voltage is coupled to the secondary coil. transformer winding is so that peak voltage will be about 2000V. The diode network only pass a fraction of the output voltage to the metal net.