The loss or breakdown of the remote control from the TV is an unpleasant event. If there is no way to restore or find an old remote, you will have to buy a new one. Beforehand, it is important to figure out how to properly match the device to a specific TV model. There are various types of remotes on sale, the difference in cost of which can differ by 10 times. How to determine which remote control can fully replace the original one? Tips and tricks on search and selection will help to deal with this.
Selection of the remote control in accordance with the marking
Each remote control supplied with the kit has its own marking. Depending on his device, you can find it:
- on the back of the case;
- on the front side of the case;
- under the battery compartment cover.
Attention! The meaning of the marking on the remote control does not correspond to this parameter of the TV, even if they are from the same set. Therefore, it is important to find exactly the marking of the remote control.
It happens that the markings on the case are worn out. In this case, it is worthwhile to find the manual for the operation of the equipment and find information there. After finding this data, it remains to go to a specialized store and buy the appropriate device.
Selection of the remote control by the selection method
If the remote control is lost and there is no chance of finding out its exact marking, you can resort to an alternative selection method. You should take several remotes from other TVs, borrowing them from friends. Check the various remotes for compatibility with your specific TV. This method is based on the similarity of microcircuits used in different brands of remote controls. It is likely that there will be a device that fully matches the TV. If you find one, you should just buy a similar device.
Also, you can focus on the appearance of the device. Choose a visually similar one in the catalog or among the assortment in the store. In this case, you should check with a consultant for compliance with a specific brand.
Advice. It is important to check whether all commands are executed by the console.
Buy a universal TV remote control
In cases where the previous methods, for whatever reason, are not possible to implement, the third option remains - to buy a universal remote control. The principle of operation of such a device is based on reading and reproducing the signal of a controlled TV. The remote control memory contains several types of signals, which allows it to successfully interact with not one, but many models.
Universal consoles are multifunctional have a number of advantages over specialized ones:
Original and non-original remotes
Choosing a remote control, one has to deal with the concepts of originality and non-originality of the device. The first category includes consoles:
- made in compliance with production technology;
- under quality control;
- supplied with TVs.
They are of high quality. Their validity period can be 7 years or more. The disadvantage is the high cost, if necessary, replacement. Also, the original models have the property of losing relevance. For those TV models that have gone out of production, they stop producing components, including remote controls. Thus, 10-15 years later, after the purchase of the equipment, the original remote controls either disappear from sale or are sold at a very high price.
The second category includes devices that are most similar to the original. However, the quality of the plastic and the assembly of the board may not be at a high level. Depending on the brand, such a remote control can last from 1 year or more. A significant advantage of such a device is its cost. Considering that technologies are improving every year and the quality of such remote controls is improving, more and more consumers are inclined to choose exactly analogs, and not original devices.
When buying a remote control, you should not always focus on popular models. This choice can be just a beautiful but expensive addition to the technique. Budget models, in most cases, have sufficient functionality.
What else you need to pay attention to for the correct purchase:
- device characteristics;
- the width of the range of action;
- the possibility of automation;
- the presence of a training mode;
- appearance and practicality (these parameters can be assessed not only in the store, but also after reviewing videos and photos of materials about the model);
- price.
Choosing and buying a remote control is not always an easy task. If you know the number and brand of the device, the likelihood of quickly finding a replacement is very high. In other cases, you will have to make an effort to find a suitable device. In any case, you can always make a choice in favor of a universal device.
How to repair a TV remote control: video
I. Ivanov
You can check the operation of the remote control in the absence of a TV using a photodiode (PD) of the infrared range. For example, the domestic FD-8K will do. The PD outputs are connected to the ground and signal probes of the oscilloscope. The control panel is positioned coaxially with the PD close to its window. Press any of the buttons on the remote control. In this case, a PWM signal with an amplitude of 0.2 ... 0.5 V should appear on the oscilloscope screen.
Most TV remote controls are the same and include:
- microcircuit-shaper of commands with a quartz resonator;
- an amplifier consisting of one or two transistors;
- LED (or two);
- keyboard and contact field.
In addition, some remote controls have an indicator LED that registers the issuance of a command.
Consider possible malfunctions of the remote control, the methodology for detecting and eliminating them.
1. There is no signal from the remote control
Check the health of the batteries. If the supply voltage is less than 2.5 V, the batteries must be replaced. At a voltage greater than 2.5 V, check the short-circuit current Isc with a multimeter. For serviceable elements, it should be equal to 1 ... 3 A. If IkzThen the remote control is opened. This operation requires certain skills and accuracy. The main task in this case is not to leave scratches on the case of the remote control and not to break the latches. To open the remote control, use an ordinary screwdriver with a thin blade (currently, there are special screwdrivers with a blade 10 ... 20 mm wide and 0.5 mm thick with a short handle on sale).
Opening the remote control begins from the side of the batteries, and first disconnect one side of the bottom cover to the entrance window, and then in the same way the other, after which the cover is easily removed.
An external inspection of the state of the printed circuit board and keyboard contacts is carried out.
Traces of dried liquid on the contact field are removed with a cotton swab moistened with alcohol. Wire breaks are eliminated by soldering thin wire jumpers.
Check for contact between the graphite bridges and the printed conductors.
Having closed any pair of contacts of the printed circuit board, check the presence of a PWM signal at the cathode of the LED with an oscilloscope.
If there is no signal, and the constant voltage is zero, check the LED by dialing. In a working LED, the resistance in the forward direction should be several tens of ohms, and in the opposite direction - several hundred kilo-ohms. A defective LED must be replaced.
A fairly common defect is a break in the LED output as a result of mechanical stress, for example, after the remote control has dropped.
Check the passage of the PWM signal from the output of the microcircuit to the LED.
2. There is no signal at the output of the remote control microcircuit
lack of supply voltage of the microcircuit;
quartz resonator malfunction;
the presence of two or more pairs of closed contacts of the printed circuit board;
breakage of conductors between the microcircuit and the contacts of the printed circuit board;
malfunction of the microcircuit.
First, the supply voltage of the microcircuit is checked: it must be at least 2.5 V.
The performance of the quartz resonator is checked by closing any of the pairs of contacts on the printed circuit board. If there is no generation at the same time, then, most likely, the microcircuit is faulty.
3. There is no signal from the remote control. At the output of the microcircuit there is a signal
Possible causes of the malfunction:lack of amplifier supply voltage;
malfunction of amplifier elements;
LED malfunction.
An oscilloscope is used to check the presence of a signal at the cathode of the LED. If there is no signal here, check its passage from the output of the microcircuit to the LED.
The most common defects in this case are the failure of the transistor of the output stage of the amplifier, violation of rations, the terminals of the amplifier elements.
4. There is no signal from the remote control. The photodiode indicates the presence of a constant voltage level. Batteries run out quickly. The LED is constantly open and a significant current flows through it
Possible reasons:breakdown of one of the amplifier transistors;
the presence of two or more pairs of closed keyboard contacts;
malfunction of the microcircuit.
The serviceability of the transistors and the presence of closed contacts are checked by "dialing". The operability of the microcircuit is checked by replacement.
5. Any command is constantly being sent from the remote control when the keyboard buttons are not pressed. Batteries run out quickly
Possible causes of the malfunction:reducing the insulation resistance between the pins of the microcircuit or the contacts of the printed circuit board;
reducing the insulation resistance between the graphite jumper and the printed conductor passing under it;
malfunction of the microcircuit.
Thoroughly rinse the microcircuit terminals with alcohol, eliminating traces of rosin, dust, dirt. On the printed circuit board, wipe the contacts with a cotton swab moistened with alcohol. Solder the corresponding pins of the microcircuit from the board. If, after that, commands from the remote control continue to come, they change the microcircuit. If the signal disappears, they look for the place of current leakage from the graphite jumper to the printed conductor. The conductor is cut off on both sides and a jumper made of insulated wire is placed (unsoldered) in its place.
6. One or more buttons on the remote control do not work
Possible causes of the malfunction:increasing the resistance of the keyboard closing contacts;
crack on the board.
The resistance of the contacts is measured with a multimeter. For working buttons, it is equal to 2 ... 5 kOhm. If the resistance is more than 10 kOhm, the button is faulty. In this case, either the "gum" is changed entirely, or the contact is repaired. Special repair kits for the remote control are available for sale. They include contacts made of conductive rubber, which are glued to the faulty contacts of the keyboard with silicone glue included in the repair kit.
The presence of cracks is determined visually. Damaged printed conductors are restored using thin wire jumpers.
Most modern remote controls provide for the possibility of converting them into a service panel. The essence of the alteration consists in installing a new or rearranging the jumper available on the printed circuit board, and the installation location on the board is indicated.
As an example, the illustration shows the RM-836 remote control for SONY TVs with the top cover removed. After installing the jumper in pos. one
The functionality of the aspect ratio change button is changed.
Now, after pressing this button twice, the TV is switched from operating mode to service mode.
Repair of remote controls.
M.KireevAfter several years of operation, the operation of the remote controls (remote controls) of TVs and other equipment is often disrupted. This is possible for several reasons: violation of the integrity of electronic components rations, oxidation of spring contacts in the battery compartment, complete or partial abrasion of the conductive layer applied to the ends of the buttons (Fig. 1),
Which are most commonly used.
To eliminate the last defect, a simple method is proposed that has been tested for several years and does not require large costs. One layer of quick-drying glue, for example, "Secunda", is applied to the button end, cleaned and degreased, for example, with alcohol, and then a piece of aluminum foil slightly larger than the area of the button end is glued on. After the glue has hardened, the protruding foil is carefully squeezed with tweezers (Fig. 2).
Practice has shown high reliability and trouble-free operation of the consoles repaired in this way.
If you often have to repair remote controls, you can make a device for monitoring their performance, assembled from available parts (Fig. 3).
The DA1 microcircuit serves to amplify the signal coming from the infrared photodiode VD1 and form a sequence of output pulses, which is fed to the DD1.1 divider. When you press any button of a working remote control, the VD2 LED will flash with a frequency of several hertz. It is convenient to mount the device in a housing measuring 100 x 40 x 30 mm (Fig. 4).
The DA1 microcircuit can be replaced with domestic counterparts KR1054UI1, KR1054XA3, KR1056UP1, KR1084UI1, taking into account the difference in pinouts.
Repair & Service
Various remotes for household appliances
Story
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The first TV remote control was developed by Eugene Polly, an employee of an American company Zenith Radio Corporation in the early 1950s. It was connected to the TV with a cable. In 1955, a wireless remote control was developed Flashmatic, based on sending a beam of light in the direction of the photocell. Unfortunately, the photocell could not distinguish the light from the remote control from the light from other sources. In addition, it was required to direct the remote control exactly at the receiver. By the early 2000s, the number of household electrical appliances had skyrocketed. To control a home theater, you may need five to six remotes: from a satellite receiver, VCR, DVD-player, TV and sound amplifier. Some of them need to be used one after the other, and, due to the fragmentation of control systems, this becomes burdensome. Many experts, including the renowned usability specialist Jakob Nielsen and the inventor of the modern remote control, Robert Adler, note how confusing and awkward using multiple remotes is. The advent of a PDA with an infrared port made it possible to create universal remote controls with programmable control. However, due to its high cost, this method has not become too widespread. Special universal learning control panels also did not become widespread due to the relative complexity of programming and use. It is also possible to use some mobile phones for remote control (via Bluetooth) of a personal computer. Some smartphones running Android, for example Redmi 4X from Xiaomi, allow you to remotely control TVs of some mass manufacturers via infrared. Remote control typesApplicationRemote controls are used for remote control of household electronic equipment (TVs, music centers, audio and video players, etc.). Miniature remote controls have car alarms. There are remote controls for controlling robots, aircraft models, etc. Even temples are equipped with remote control systems. In general, the remote control can be used in any device with electronic control. Household equipment remote controlA consumer electronics remote control is usually a small button device, battery powered, that sends commands via infrared radiation at a wavelength of 0.75-1.4 microns. This light is invisible to the human eye, but is recognized by the receiver of the receiving device. Most remote controls use one dedicated microcircuit, either packaged or unpackaged (placed directly on the PCB and sealed with a compound to prevent damage). Previously, only the basic functions of the device (switching channels, volume control, etc.) were taken out on the remote control, now most of the samples of modern consumer electronics on the body itself have a limited set of controls and a full set of them on the remote control. For the first remotes to transmit one function, command (single-channel remote control, with one button), the presence / absence of the transmitted signal itself was enough. But even then only if it was transmitted through an anti-jamming channel (for example, a wire), otherwise external interference (rays of the Sun, etc.) led to a false alarm. The first wireless remote controls used an ultrasonic communication channel. For consoles with several functions, a more complex system is required - frequency modulation of the carrier signal (it is also used to create channel noise immunity) and coding of transmitted commands. Now digital processing is used for this - the transmitter microcircuit (in the control panel) modulates and encodes the transmitted signal, its demodulation and decoding takes place in the receiver. After demodulating the received signal, appropriate frequency filters are applied to separate the signals. To read the code of the pressed button, the method of scanning the lines of the matrix of buttons is usually used (a similar method is used in computer keyboards), but in the remote controls of household appliances, the use of continuous scanning would require energy and the batteries would quickly run out. Therefore, in standby mode, all scanning lines are set to the same state and the console processor is put into sleep mode, turning off the clock generator and consuming practically no energy. Pressing any button on the input scan lines changes the logic level, which causes the processor to "wake up" and start the clock generator. After that, a full cycle of keyboard scanning is started to determine the button that caused the wake-up. The one-button-one-line method is usually not used due to the large number of buttons on modern remote controls. After determining the pressed button, the remote control generates a message containing the remote control code and the button code. Household remote controls do not have feedback, which means that the remote control cannot determine whether the signal has reached the receiver or not. Therefore, the signal corresponding to the pressed button is transmitted continuously until the button is released. When the button is released, the remote control goes back to the standby state. On the receiving side (for example, on a TV), data is received: the remote control code is checked, and if this code matches the specified one, the command corresponding to the pressed button is executed. The transmitter and receiver (of the remote control and the device) must use the same coding techniques and modulation frequency transmitted data, otherwise the receiver will be unable to receive and process the data sent to it. ModulationUsually, consoles use one carrier modulation frequency (that is, the radiation frequency of the IR LED) - both the console and the receiver are tuned to it. Modulation frequencies are usually standard - they are 36 kHz, 38 kHz, 40 kHz (Panasonic, Sony). Frequencies of 56 kHz (Sharp) are considered rare. Bang & Olufsen uses 455 kHz, which is very rare. Using a receiver with a modulation frequency that does not exactly match the transmitter frequency does not mean that it will not receive - the reception will remain, but its sensitivity can drop very much. Signal transmission is carried out by the radiation of an IR LED with an appropriate modulation frequency. For frequencies from 30 to 50 kHz, LEDs with a wavelength of 950 nm are usually used, and for 455 kHz, special LEDs with a wavelength of 870 nm are used (specialized receivers TSOP5700 and TSOP7000 are oriented to this wavelength and high modulation frequency). Several such modulated transmissions and cancellations ( bursts of impulses) form coded parcel(see below). An infrared signal receiver consists of several stages of amplifiers and a demodulator (frequency detector) and is sensitive to the signal up to -90 dB (most amateur radio circuits have a sensitivity of up to -60 dB). Also, almost all mass-produced IR receivers have an IR filter (dark red lens or plate). The IR receiver module itself has only three pins: Nutrition, Land, Data output. CodingEncoding of transmitted data is used to recognize many different commands of the remote control. Now the following two schemes for encoding the transmitted data are mainly used:
Before sending encoded data, the remote control always sends one or several synchro-signals in order for the photodetector to adjust the receiving circuit (synchronized with the remote control in sensitivity and phase).
Console manufacturers are not inclined to adhere to any general standard data coding protocols and have the right to develop and apply more and more new protocols for their equipment. A more complete list of protocols: NEC (repetitive pulse), NEC (repetitive data), RC5, RC6, RCMM, RECS-80, R-2000 (33 kHz), Thomson RCA (56.7 kHz), Toshiba Micom Format (similar NEC ), Sony 12 Bit, Sony 15 Bit, Sony 20 Bit, Kaseikyo Matsushita (36.7 kHz), Mitsubishi (38 kHz, preburst 8 ms, 16 bit), Ruwido r-map, Ruwido r-step, Continuous transmission 4000 bps and Continuous transmission 1000 bps. They can be discharged in six months only because of the high self-discharge current of them, besides, the long service life of one charge will not recoup the cost of the battery. Problems with wireless remote controls
The presence of a signal from the remote control can be checked by looking at it through a camcorder or digital camera, while pressing the buttons on the remote control. CCDs in consumer photography and video equipment usually see the infrared range. |
In our time, television has reached its apogee of development. Many people watch TV several times a day and the remote control in this case is an integral part of the TV. Adults sadly recall the times when they had to get up from the couch or chair every time to change the channel. Now everything is much easier - just press one button on this "magic wand" and you are watching another channel. But how does the remote work? Let's take a look inside. The principle of operation of the remote control is that for its operation it is necessary to press a button that is responsible for a particular function. This push will then turn into an infrared light signal for the TV to receive. If you remove the back cover of the remote control, you will see only one detail - a printed circuit board with many dots and lines. Almost all remote control devices use a typical set of components. The first is an integrated circuit (also called a chip) with the serial number "TA11835". On the right side of the chip is a diode, a transistor (black), a resonator (yellow), two resistors (green), and a capacitor (dark blue). There is a resistor (green) and a capacitor (brown disc) near the battery terminals. With this circuitry, the chip determines which button was pressed. Then it translates the "pressed button" into a sequence of characters, a kind of Morse code, since each button has its own code. The chip then sends this encoded signal to a transistor, which amplifies it.
Printed circuit
If you untwist the printed circuit board and pull it out of the console, you will notice that it is a thin fiberglass plate with thin copper "stripes" engraved on its surface. Various electronic parts are assembled on a printed circuit board. "Printing" copper strips onto fiberglass sheet is an inexpensive process. In addition, nowadays it is not very difficult to install parts (for example, chips, transistors, etc.) on a fiberglass plate, and then solder it all with copper wires.
If you look at the diagram, you can see a set of contact points that correspond to each individual button. The buttons themselves are made of a thin elastic material. Each button has a corresponding tiny, conductive disk. When the disc touches the pins on the printed circuit, a connection is made and the chip senses a signal that they are connected. At the end of the printed circuit is an infrared LED, also called a light emitting diode. Many light emitting diodes produce visible light, but those found in remote controls emit light invisible to the human eye. But if you have a video camera, then you can see this light through a video finder. To do this, you need to point the remote control at the camera and press any button. The infrared light will be reflected in the video finder.
Basically, the basic principle of all remote control devices is as follows: you press a button and the main chip senses the contact of the button with the board and determines which button was pressed. Then it reproduces the coded signal of this button and sends it to the light-emitting diode, which converts the signal into infrared light. A sensor on the TV picks up this signal and executes the command given to it.
Gone are the days when, in order to switch TV channels on a TV, add sound on a tape recorder, or rewind a cassette, you had to get up from the couch and go directly to the knobs and switches on an electronic device. Of course, there was nothing wrong with that - once again raising your "fifth point" is very good for your health, but nevertheless, technical progress is inexorable and thanks to it, a remote control appeared, without which, in fact, control of not one of the modern electronic devices.
Consider how this miracle of technology works. In fact, everything is quite simple, if you do not go into details. A remote control, for example, a tricolor TV remote control, by itself does not perform any functionally complete task. It works only in tandem with the device (TV, tape recorder, air conditioner) with which it originally comes in the kit or for which it is intended.
The remote control itself contains a microcircuit that converts the information about the pressed key into a sequence of electrical impulses that are fed to the emitter (usually an infrared LED). In turn, the emitter transmits the already visually converted signal to the photodetector, which is located in the electronic device itself (TV, tape recorder or air conditioner). Having received the information in a visual form, the photodetector converts it into a sequence of electrical impulses, which are fed to the microcircuit of the device control unit. And she, in turn, already generates signals to control the functions of a TV, tape recorder or air conditioner.
That is, after you have pressed one of the buttons on the remote control, the signal is first converted into a light form, and then back into an electrical signal. The convenience of such a system is that a very large amount of information can be recorded using a sequence of pulses (electrical signal). This allows not only to give the remote control more functionality, but also to use a unique code for almost every electronic device, so as not to cause false alarms of other electronic devices that do not need to be controlled at the moment.
Mainly, infrared remote control is used to control household electrical appliances 
management. This means that the transmission of the information signal from the emitter to the receiver is carried out in the infrared light range. The human eye cannot see in this range, so physically we do not notice the blinking of the emitter. On the one hand, this is very good - control signals do not interfere, for example, with watching TV. However, on the other hand, we cannot visually see whether the remote control is working or is broken. But this is not such a big problem. To check the operation of the remote control, it is enough to have a mobile phone with a camera at hand. Turn it on in camera mode and point the camera at the LED on the remote control. When you press any of the keys, the operating panel will give out periodic flashes that are clearly visible on the mobile screen. That's all.
