The radio does not appear in the list of necessary electrical equipment on board the car and is not even included in the basic equipment of some branded car manufacturers. However, this is the most popular device that accompanies a car enthusiast throughout the history of car use. That is why do-it-yourself radio repair is still a fairly relevant topic. Some breakdowns can be repaired independently. When the radio does not turn on, do-it-yourself repair is the first thing that comes to mind for a car owner. And often even minimal knowledge on this topic helps to solve the problem.
Main causes of breakdowns
There are quite a few reasons for the radio to malfunction or simply turn off its power. But there are a number of those that are considered basic:
- Despite the fact that there are practically no moving parts in the radio, with the exception of models equipped with DVD, dust and dirt canlead to breakage. The finest particles can not only clog the motor drive, but also clog the reading eye, which leads to the radio no longer recognizing the disc. Also, USB connectors can become clogged with dust, which means that the radio will not be able to read information from media.
- Incorrect installation of the device can lead to a failure in the power system and when the volume is increased, for example, the device simply does not have enough power and it turns off.
- A voltage drop in the car's electrical network or a short circuit can lead to a blown fuse in the circuit.
- Incorrect use of the device may cause physical deformation - broken buttons, knobs and moving parts and connectors.
Repair Tools
In order to repair radio tape recorders with your own hands professionally, you need to take care of purchasing special tools and equipment. First of all, this is a set of screwdrivers with various stings. You may have to deal not only with the repair of JVC radios with your own hands, which are considered the top quality, but also with other models. You need to understand that different brands use bolts with different grooves - stars, hexagons, crosses or a simple slot. You will need the appropriate tool or a multi-purpose screwdriver with interchangeable bits.
You will definitely need side cutters, pliers, a soldering iron, and preferably two - powerful up to 100 W and small up to 45 W.
To determine the open circuit in electrical circuits and ratingpower on the power supplies will need a tester - a multimeter. In general, this is all that is needed to repair Pioneer radio tape recorders with your own hands and other models.
The radio does not turn on or the screen does not light up
How to determine that the radio is broken? It could be anything. She does not play, does not turn on, does not see the CD or USB flash drive, the monitor went out, the button fell off, and so on. The main failure is the lack of response to the "On" button and the missing screen backlight. The reason for this malfunction is a malfunction of the power supply. It does not supply the correct voltage.
To verify this, after providing access to the power supply, you need to measure the voltage on pin 2 of the CN701 connector. The voltage should be 14 volts at the connector. If not, then most likely the transistor or zener diode burned out. It must be replaced with the same one by removing the damaged element from the printed circuit board. Sometimes the signal to turn on the device does not pass due to a power failure on pin 40 of the IZ901 connector.
Sound disappeared or hum appeared
Do-it-yourself radio repair allows you to restore power to the device. You can also try to fix problems such as no sound after turning on or the appearance of a hum in the speakers. First of all, the reason may lie in the absence of a signal from the StandBy system. Usually 4.8 volts are lost at the IC901 connector on its 4th pin. In this case, it will be necessary to replace the entire controller or clean the contacts on the power amplifier.
If there is a background that increases with increasing volume, you need to check the nominal voltage at the bases of the amplifier stage transistors. If the device showed "0" on the basis of the transistor, then the microelement will have to be changed. Sometimes the presence of the background is affected by the volume control button itself. This is manifested by the fact that the sound level does not change when the knob is turned in any direction. In this case, it will be necessary to replace transistor Q802.
Any disturbance of the sound - the background or the inability to control it - is a malfunction in the amplifying stage. Most often, containers dry out. It is easy to change the capacitor, you can determine the faulty one directly on the board, although for the purity of measurements it is best to remove it from the circuit.
The device does not play files from disc and USB media
The main reason why a file on a disk or on a flash drive is not played is that it is written in a different format than the one that the radio can read. In this case, you do not need to repair anything, you just need to overwrite the file in the format familiar to the radio. Usually the most common is MP3.
If information is not read only from a CD, then most likely this is due to contamination of the reading eye with a laser and a photocell. You can restore work using a special cleaning disk or manually, but you will have to completely disassemble the radio case, since the peephole is located in the middle of the device.
In rare cases, laser power fails. Troubleshootingit is necessary to measure all the outputs from the power supply with a tester, comparing the results with the rating recorded in the circuit.
Sometimes the reason is in the cable connecting the moving part of the laser eye with the rest of the radio circuit. Do-it-yourself repair of the radio cable consists in pulling up the bots holding it on the board.
Buttons on the front do not work
Do-it-yourself Chinese radio repair reviews most often reflect mechanical failures, such as failure of the buttons on the front panel or simply falling out of the device. This problem most often occurs with low-quality and cheap models from unknown manufacturers or on obvious fakes. A broken or dropped button will need to be replaced.
If it is in place, but there is no reaction when pressed, you need to restart the system and return the settings to the factory standard. To do this, the power of the radio is completely cut off, that is, all power connectors are turned off, and after 3-5 minutes everything is connected back. During the shutdown, all microcurrents accumulated in the capacitors will expire, and the processor will return to the factory firmware.
Radio gets hot
You can repair radio tape recorders with your own hands, if after a short work it noticeably heats up. Most often, a device with such a problem also turns off on its own. The reason is poor contact between the power wire and the power supply.
To eliminate it, it is enough to check all contacts andclean them up, remembering that electronics is the science of contacts.
The appliance may become warm due to insufficient ventilation. Most often, such a problem is observed with the Pioneer radio. But it manifests itself in the hot season, especially if the device is installed in a car without air conditioning.
Many craftsmen who repair breakdowns of Pioneer, JVC and other original radio tape recorders begin repairs with a hard restart of the system, that is, resetting the settings to factory settings. Often this helps. As experts say: seven troubles - one reset.
No radio signal
If the radio does not work, do-it-yourself radio repair is also possible. The problem manifests itself in such a way that when you turn on the radio mode, only noise and interference are heard.
Most often the reason is that the antenna just fell off the device. This is easy to check - the antenna connector is located on the back of the radio. It does not matter which antenna, active or passive. To receive a stable signal within the city, the wire itself from it is enough.
If, with the antenna turned on, the scanner still cannot tune in to any channel, then the cause may be a leaking or dried capacitor in the radio receiver unit. You can determine the damaged element using a tester or even visually. After replacing the element, the radio starts working.
Conclusion
Modern radio is a fairly simple device with a minimum of electronic elements that can break down. The processor itself- This is a microcircuit that very rarely fails. And the fact that around it - capacitors, resistors and fuses - is easy to change by dropping it out of the circuit. Well, we must not forget about the quality of contacts. It is unacceptable to use the so-called "twisting" wires. You need to connect them only through special connectors. By observing the conditions for proper installation, you can protect the device from damage. You should also be careful with the device during operation. Then it will last for many years.
