Amplifiers, despite their simple appearance, are considered one of the most complex boards. Each amplifier has two separate parts. One part is Switching power supply and the second part is amplifier. Since this circuit works with sound, the presence of noise is obvious. Different filters are often used to eliminate sound noise and voltage noise. Inductor and capacitor at the input of the amplifier circuit are for voltage noise. More capacitors play an important role in storing the voltage and in the term not reducing the amplifier. Most amplifiers have protective fuses at the beginning of the voltage circuit. Often there is a reverse diode to protect the reverse connection of the voltage, which causes the fuses to break due to the reverse connection. MOSFETs are MOSFETs for switching in the primary power supply section of the circuit. A toroidal transformer is available for switching in amplifiers. Increasing the voltage is necessary to have a louder sound. This device has a primary and secondary ground, that is, it has two cold parts that should never be in contact with each other. There are two separate amplification sections in the amplifier section. The preamplification section and the main amplifier section. The positive transistor pnp transistor and negative npn transistor are the main factor in producing loud sound. Zener and resistance are used to feed the pre-amplification section to reduce the voltage, which are one of the main reasons for the device's sound failure. Always replace zener and resistors even if they are good. Due to heat and continuous work, these parts wear out quickly. To construct this type of boards, enter the Signal generator signal on 50 to 300 Hz and with a sine wave shape through rc. With the help of the oscilloscope, which is in dc mode, follow the path of the signal to the coupling capacitor of each of the drivers. In the driver section, differential transistors and current determining transistors have the most failures. In general, repairing these devices is not difficult, but you must know the circuit completely. Repairing electronic boards requires experience and knowledge. We can never accidentally diagnose and repair the circuit. So it is better to do this by knowing the device and seeing the necessary training. The construction of any electronic board is a window to knowledge that you will discover with the passage of time and gaining experience in the new world of electronic circuits. To subscribe to the channel, click on the following link: / @electronic4hame My training in English (my second channel): • Why does the satellite receiver not t... The first lesson of Ampli training course Khurdu fire: • First lesson - class AB car amplifier ... Making an amplifier with positive and negative voltage: • With positive and negative transistors, amplifier S... Making an amplifier with two MOSFET number: • Making a stereo amplifier with two MOSFET numbers... Making a microphone for the amplifier: • With a 2030 TDA IC and a microphone... Making an amplifier with I C TDA 2030: • Making an amplifier with IC 2030 TDA ... Making a bass and treble circuit for an amplifier: • Bass and bass circuit for your own amplifier... Thank you Your support ❤️❤️❤️ I also have several training courses. The best job in electronics is to learn circuit analysis. The sooner you start, the more time you will have. Our website for preparing courses: https://www.elecma.ir Our training courses include 1) Analysis of switching power sources based on circuit and schematic 2) Analysis of electrical protection circuit board on map and description Working principles of circuit 3) Analysis of computer power circuit. Complete analysis of 4 different maps with available AC types 4) Construction of a variable power source with high and low current (with appropriate transistor) 5) Installation of flash player in the car broadcast in principle along with Construction of the signal circuit without change in the broadcast circuit 6) Review and analysis of the car battery charger circuit 7) Scientific and practical review of welding inverter or welding machine 8) Car amplifier training course 9) 220V power inverter training course 10) Changing the book-bee power supply to the construction of the short-circuit circuit on our website for preparing courses https://www.elecma.ir 00:00 Description of Khordu amplifier circuit 01:10 Primary and secondary cold ground 02:18 Amplifier circuit voltage measurement 04:20 Generator signal input waveform and display on oscilloscope 05:20 Repair recommendations in the amplifier