For many people, the radio is an indispensable source of information. If it fails, there are two options - try to fix it or buy a new one. Repairing in a workshop is usually not profitable, so it is worth trying to fix the radio yourself.
Instructions
Step 1
In many cases, a radio receiver malfunction is not associated with the failure of some parts, but with poor contacts in the power circuit. If the receiver does not show signs of life, then the troubleshooting should begin with checking the supply circuits.
Step 2
Most modern radios are connected to a car network or work through a 220 V power supply. Using a tester (multimeter), check whether the receiver is receiving power. To do this, first disconnect the power cord from it and check if the correct voltage is supplied to its connector. If it does, open the radio, plug in the cord, and check the circuit before and after the switch. Very often it is the power switch that is faulty.
Step 3
If the receiver turns on, but does not receive radio stations, you will need its circuit diagram for repair. Since all radio electronic equipment currently being produced is supplied without circuits, it will have to be found on the Internet. Type in the search bar the exact name of your receiver and the words "concept". The chance of finding her is high enough.
Step 4
The circuit is found, you can start troubleshooting. Turn the tuning knob and listen for any sounds coming from the speaker - noises, crackles, etc. If so, this indicates the health of the audio output stages (low frequency amplifier). This means that the malfunction is located in the section from the antenna to the bass amplifier.
Step 5
Check the antenna carefully - a ferrite rod with coils wound on it. Inspect the range switch for poor contact. Check all switch circuits on the switched off receiver; if necessary, disassemble it and clean the contacts.
Step 6
If the antenna and the switch are in order, for further work you will need high-impedance headphones - for example, TON-2 or any others with an impedance higher than 1000 Ohm. Study the schematic diagram, find high-frequency amplifying stages - it is to them that the received signal comes from the antenna. Perhaps one of their elements is out of order. Having connected thin probes to the headphones, touch the common wire ("ground") with one of them, and the collector of the transistor of the tested stage with the second.
Step 7
The appearance of sound in the headphones indicates that the receiver circuits are in good working order before this section. Check the next cascade - if there is no sound, it is necessary to look for a malfunction in this area. Most often, the stage transistor or one of the capacitors is faulty.
Step 8
Capacitors in electronic equipment fail quite often, so always pay attention to their appearance. Swollen, dry, or leaky capacitors need to be replaced. A large current consumption can indicate a malfunction of the power filter capacitors.
