How to repair a home theater

The horror that covers the owner of a home theater in case of failure of an expensive device is quite understandable. What to do? Self-repairing household appliances at home is a way to save money and your own time. If you possess at least initial technical knowledge, then try to consistently understand the cause of the breakdown and eliminate it.

Problem specification

First, it is also the main difficulty encountered in repairing fault diagnosis. Home cinema in the simplest approximation consists of four devices:

• signal source;
• television;
• acoustic speakers;
• receiver or amplifier.

First of all, you need to understand which of the components does not work.Suppose there is confidence that there is a normal input signal, and the screen remains dark. So, the monitor is broken. If you have certain skills, you can try repair it yourself. If there is no sound, the speaker may break down. If there is sound, but it turns off after a while, it means that the amplifier is broken. No disc loading - the signal source is not working.

Minimizing the loss of up to one device, you can decide on the repair.

The hand immediately reaches for the phone to call a specialist from the service center. Do not hurry! It is possible that the breakdown of the cinema can be fixed with your own hands at home, having saved a lot on the invitation of a professional.

The first independent step

AT home theater system sure there is a bunch connecting wireswhich ends with connectors (the exception is only wireless acoustics). During operation, the individual components of the cinema, of course, a little bit, but moved. If there are animals at home, and the wires are not laid in special channels, it is easy to assume that they were played with these wires.In addition, contact pins may oxidize.

The first stage of repair is considered a visual inspection of the connecting wires.

If they are in order (not pressed with furniture), then each connector must be removed, cleaned with alcohol or an eraser and inserted into place with an effort. We make a test inclusion and, if the malfunction has not disappeared, go ahead.

Power as the basis of device vitality

Next, we check the power supply of the device, since in 90% of breakdowns the problem is exactly power supplies. They are used as linear power supplies (they are quite easily repaired at home), and pulse (repair requires certain skills).

In any kind of power supply necessarily present circuit breakers, from which check any repair begins. It is necessary to pay attention to the fact that many firms have abandoned the use of traditional (thread in the flask) fuses, and replace them with resistors of a small value. They more accurately perform the function of protection, due to a strictly fixed current limit. The reasons for the failure of the fuses are only two:

• ripple in the network, well above the norm;
• failure (usually short-circuit) in the scheme of the device itself.

A common cause of a power supply failure is the failure of electrolytic capacitors.

It is necessary to visually inspect all electrolytes. If the barrel of the condenser is swollen, there is a leakage of liquid - feel free to replace. The remaining capacitors are tested with a tester: it should not ring in any direction. If there is no confidence in the measurement, it is necessary to unsolder one leg of the capacitor.

Next comes the turn of verification bridge rectifier diodes. Any of them should show a short circuit in only one direction. It is also a good idea to check varistors and thermistors of protection, but this is not always possible using only a tester.

On models with toroidal transformers put thermal fuse. To check it you need to unsolder from the scheme. Like the standard one, it can burn out from a sudden drop in input voltage, protecting the primary winding of the transformer. Therefore, when a transformer fails, it is not necessary to throw it away. Better find the bump under the braid, remove the thermal cutout from under it, replace it with a piece of wire for the first time. Such repairs will allow the cinema to work more.

Switching power supplies In home theaters it is much more complicated in its structure than linear ones. Typically, key elements burn out - thyristors, high-power transistors, microcircuits. When repairing a pulse unit, a load is needed, the so-called equivalent. At home, it is usually not.

If a pulsed power supply fails, it is better to contact a specialist.

Cinema Sound Problems

Often complain about the loss of sound in home movies after a short segment of normal operation. For example, in Panasonik home theaters, it is displayed f61 error. This is usually due to a failure. power amplifier or bass booster. Their unstable work leads to the fact that the output to the speakers is turned off.

If the power supply is OK, the reason is usually in the preamp. It is worth paying attention to the diodes from which the voltage of 2.5 volts is applied to the digital sound controller. It happens that these diodes work in the “leakage” mode: they work, or they don't. Replacing an item makes repair successful and home movies work again.

Sometimes the lack of sound is connected with trivial causes and it is not at all necessary to run away from the workshop. One of these breakdowns is lack of sound control. This is due to a defect in the operation of the position of the sound switch on the front panel. It must first be elementary soldered, eliminating bad contacts. If it does not help, it is necessary to remove and clean it, after dismantling. As you can see, everything is very simple.

You can often meet subwoofer failure, with fully working the remaining speakers. The search must begin with a survey that leads to the subwoofer wires: it is necessary to ring his tester. Not finding damage, you need to check the connectors in the subwoofer itself, and in the cinema.

If this attempt does not give positive results, two options remain:

• the subwoofer itself is broken;
• cinema sound amplifier failure.

Repair of such complexity is undesirable at home, it is better to contact the workshop.

No external signal

The source of the external signal in the cinema at home is usually DVD player. When it starts to “limp”, the picture “hangs up” or the disk simply does not read. It is necessary to begin repair with an elementary cleaning of a lens with special napkins.

It is worth paying attention to the quality of playable discs. If the disk "showered", it pollutes the head.

If the simplest method does not help, then you need to remove the drive. Often the problem lies in his carriages, over time, their mechanics wear out. Operation carriage replacement extremely simple and quite affordable at home.

The next stage of repair may be motor replacement in a DVD drive or laser head. But these operations are best performed in a specialized workshop.

There are cases of failure expensive processor. This is usually associated with an extremely simplified stabilization scheme in the device itself. As a result, the processor gets very hot and fails. In order to avoid this trouble, it is best to invest in a high-quality voltage regulator, and turn on a home theater through it. At the same time there will be protection against peak voltages. Benefit voltage regulator for tv also obvious: this sensitive technique suffers from voltage surges no less than a home theater.