The Russian market is flooded with inexpensive portable LCD TVs, mainly made in China. The circuitry of such TVs is not very diverse. As a rule, for their production a simplified version of the TV chassis for a cathode ray tube is used - a microcontroller, a video processor (for example, from SANYO: LC863324 + LA76810) and, as an LCD panel interface, a controller from SHARP IR3Y26. Much less commonly used is a PANASONIO chipset (M37160+M61260). Repair of such chassis is described in detail in. This material examines a rather rare version of a TV chassis based on a single-chip TV processor MST726A from MStar Semiconductor, specially designed for use in portable LCD TVs.
General information
Competition in the market for integrated circuits (ICs) for budget TVs remains greater than ever. TV manufacturers are concerned about the crisis and therefore their attempts to gain positions in the sector of low-cost TV models are understandable. One company that has managed to improve its position in the low-end chip manufacturing sector is MStar. Thus, at the beginning of 2009, its share in this IC market increased to 15%, and it managed to overtake such well-known manufacturers as TRIDENT ZORAN and NXP Semiconductors. The reason for this growth was the development and production of specialized microcircuits, in particular, a TV processor combined with a video processor - MST726A. A special feature of this microcircuit is the presence, in addition to the indicated nodes, of an analog interface for LCD panels with diagonals of 3.5...8 inches, so to produce a portable TV, it is enough to add radio channel and power nodes to the MST726A IC. Chinese manufacturers quickly took advantage of this fact, in particular, portable TVs with 7- and 8-inch screen diagonals were released under the DESO brand: “Deso TV-705” (chassis JV-777/705726), “Deso TV-705D” (chassis JV-705D) 705d-726A) "Deso TV-805E" (chassis JV-V805E-726A) and "Deso TV-809" (chassis JV-809-726A). Let's look at the operating principle and repair of these TVs using the example of the "Deso TV-705" model.
Electrical circuit diagram
The electrical circuit diagram of the Deso TV-705 model is shown in Fig. 1 and 2.
The circuits of other DESO TV models have minor differences regarding the audio circuits.
As can be seen from the circuit diagram, the chassis is based on a specialized IC for use in portable LCD TVs MST726A.
The block diagram of this IC is shown in Fig. 3.
Rice. 3. Block diagram of TV processor MST726A
Let us present the main functions of the components of this microcircuit.
Video decoder
Compatible with NTSC, PAL and SECAM input formats;
2D NTSC and PAL comb filter for separating brightness and color signals from the PTsTS;
One S-video and/or several PCTS inputs;
Subtitle support.
Analog input
RGB input for signals from a PC, camcorder or GPS device;
Supports video signal formats 480i, 480p, 576i, 576p, 720p, 1080i;
Supports RGB signal resolutions 640x480, 800x480 and 800x600;
3-channel 10-bit ADC for RGB signal;
Synchronization from composite (СSYNC), separate (HSYNC+VSYNC), SOY and SOG signals;
On-chip clock synthesizer with PLL;
Auto-adjustment of position, phase, gain and auto-mode detection.
Chroma Processor
Adjusting brightness, contrast, color and tone;
Edge enhancement unit (LTI);
Color Transition Improvement (CTI) node;
Black (BLE) and white (WLE) expansion schemes;
3-channel gamma correction adjustment.
Processor scaling
Compatible with analog LCD panels with resolutions of 960x234, 1200x234 and 1400x234;
Support various display modes;
Horizontal panoramic zoom node.
Digital PWM controller
Programmable operating frequency and pulse period with output voltage stabilization;
Programmable output stabilized current;
Switching operating frequency within 40-70 kHz and synchronization mode from HSYNC;
Flash modes (150...300 Hz) and continuous to stabilize the output current, synchronization mode from VSYNC;
Programmable protection level for error detector input voltage.
Other functions and features
Integrated microcontroller;
3-wire serial interface;
Built-in OSD generator, 256 programmable fonts, 16-color palette, 12-bit color resolution;
3-channel 8-bit DAC for RGB outputs (range 0.1...4.9 V);
Interface for external OSD generator;
Built-in circuits for adjusting the levels of AC/DC components in the signal;
128-pin PQFP package.
The two inputs of the PCTS IC MST726A (pins 20-21 and 22-23) receive signals from the output of the radio channel (TV_CVBS+ signal from the RT9 RT13 divider in Fig. 2) and from the LF input connectors CN0 (AV1), CN5 (AV2). The last two signals are combined and supplied to one input U4 - pin. 22. RGB (pin 7-13) and S-video (16-19) inputs are not used on this chassis. As a result of processing the PCTS, analog RGB signals (pin 106, 110, 112) are generated at the output of the U4 microcircuit, which are sent to the LCD panel through the CN6 connector (pins 22-24). In addition to these signals, U4 generates other synchronizing and control signals for the operation of the panel (pin 84-99). The purpose of the LCD panel interface signals is given in table. 1.
Table 1. Purpose of LCD panel interface signals
| Contact CN6 | Designation | Enter exit (I/O) | Description |
| Logic and driver supply voltage |
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| Negative supply voltage for frame drivers |
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| Positive supply voltage for frame drivers |
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| Starting impulses for personnel drivers |
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| Shift pulses for frame drivers |
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| Selecting the "top/bottom" mode |
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| Resolution of frame driver outputs |
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| Common electrode of LCD panel |
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| Common electrode 1 LCD panel |
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| Line scan mode "left/right" |
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| Selecting the scan mode |
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| Resolution of line driver outputs |
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| Start pulses for line drivers |
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| Shift pulses for horizontal drivers |
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| LCD panel supply voltage |
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| Analog signal input R |
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| Analog signal input G |
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| Analog signal input B |
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| Analog part supply voltage |
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| "Ground" of the analog part |
We list the external components of the TV processor that ensure its functioning:
Hard reset node R54 C48, connected to pin. 72;
Resonator Y1 (12 MHz), connected to pin. 121, 122;
Non-volatile memory chip (EEPROM) U5 (AT24C16), it stores user settings, connected to U4 via the I 2 C interface (pin 66, 67);
Flash memory U3 (PM25LV010), which stores the control program for U4, is connected via a 4-wire serial bus (pin 57-60).
On the pin. 70 and 71 U4 generate control signals for LED mode indicators. Signals through switches on transistors Q11, Q12 are supplied to connector CN4, through which the display board and IR receiver are connected to the main board. The signal from the IR receiver goes to the pin through the same connector. 65 U4.
The chassis in question uses a channel selector (tuner) with a digital frequency synthesizer of the TDQ-3T-5 type (Fig. 2). Control commands and data (band selection, frequency code) are supplied to the tuner via a separate I 2 C bus from the TV processor (pin 63, 64). From the output of the IF tuner, through a resonant amplifier on transistor QT3, the signal is received by bandpass IF filters SAW1 (K9453M), SAW2 (K3953M), with the help of which the IF audio and image signals are separated, respectively. From the outputs of the filters, the signals go to the inputs of the TDA9886TS microcircuit (pin 2223 and 1-2). This is a multi-standard (PAL/SECAM/NTSC) demodulator of IF signals with both positive and negative modulation, including processing of AM and FM audio signals. To operate the demodulator PLL system, a reference frequency of 4 MHz (pin 15), stabilized by Y2 quartz, is used. On the pin. 14, an HF AGC signal is generated, which is fed to the tuner input (pin 8).
Like the tuner, the demodulator is controlled via the I 2 C interface (pin 10, 11). The output signals of the demodulator - the 2nd audio IF and PTsTS (with pins 8 and 17, respectively) are fed to the inputs of the processing paths for these signals (the PTsTS signal is pre-amplified in power by a repeater on QT1).
The swing of the TDA9886 input differential signals (pins 1, 2 and 23, 24) must be at least 60...100 µV, and the output - 540...600 mV per pin. 8 (audio low-frequency signal) and 2...2.3 V per pin. 17 (PCTS).
The tuner and the TDA9886TS chip are powered by a 5 V stabilizer U1 (MP1410) through a switch on transistor Q1, controlled by the TUNER_PW signal with pin. 62 U4. In this case, the current consumed by the TDA9886TS microcircuit should be 60...70 mA.
The AUDIO sound signal is then sent to the pin. 4, 11 switch IC1 (4052). Other inputs of the switch receive stereo audio signals from the LF input connectors (AV1R/L - on pin 15, 2, AV2R/L - on pin 12, 1). The switch is controlled by signals A and B from the pin. 75, 76 U4. The output signals of the switch (pin 3, 13) are fed to the audio amplifier U7 (TDA7496). This is a two-channel amplifier with an output power of 2x2 W (at U S = 12 V, R L = 4 Ohm, THD = 10%, U VOL = 5 V, U MUTE = U STBY = 0 V) with volume control, sound blocking and standby modes. Amplifier inputs - pin. 4, 9, outputs - pin. 14, 17, analog volume control - pin. 6, MUTE mode - pin. 12, STBY mode - pin. eleven.
All chassis components are powered from a household network through an external AC/DC adapter 220/12 V. It is connected to the TV via the CN1 connector (Fig. 2). From here, a voltage of 12 V through fuse F1 and a filter is supplied to the step-down DC/DC converter U1 (MP1410), which generates a voltage of 5 V with a load current of up to 2 A. This voltage powers the tuner, radio channel, LCD panel, EEPROM, and audio switch. To power the TV processor, voltages of 3.3 and 2.5 V are generated from 5 V using stabilizers U2 (AMC1117-3.3V) and U11 (AMC1117-2.5V), and 1.8 V using the quenching resistor R76.
To power the LCD panel drivers, fairly high constant voltages of + 15 and -15 V are required. These voltages are generated using PWM controllers included in the U4 TV processor. From the PWM outputs (1st channel - pins 45-46, 2nd channel - pins 48, 49), high-frequency pulses are supplied to voltage multiplier rectifiers (Step-Up Circuit node in Fig. 2), from the outputs of which the voltages +15 and -15 V are removed. To stabilize the voltages, the feedback signals CP1_FB and CP2_FB are removed from the outputs of the rectifiers and supplied to the inputs U4 - pin. 44, 47.
The electroluminescent backlight lamp (CCFL) of the LCD panel is powered by a step-up DC/AC converter on elements U7, T9 (Fig. 2) and PWM in U4 (pin 27, 35, 36). PWM pulses control the field-effect transistors of the U7 assembly, connected in a bridge circuit. The load of the circuit is the winding of the transformer E7. The pulse voltage is removed from the secondary winding and supplied to the CCFL lamp through a voltage multiplier. As in the previous case, to stabilize the converter voltage, the feedback signal DPWM_FB is removed from its output and sent to the PWM control input - pin. 27 U4.
The DC/AC converter is powered directly from a 12 V network adapter, the power circuit is protected by a fuse and a choke (against impulse noise). Converter output parameters: U = 420...480 V, I = 7...8 mA.
Let's look at typical malfunctions of TVs made on the JV-777/705-726 chassis and its versions.
Typical faults and methods for eliminating them
No sound, no picture, dark screen
If the indicator is red, press the POWER button, the indicator color should turn green. If this does not happen, check the serviceability of the stabilizers 3.3 V (U2), 2.5 V (U11) and 1.8 V (formed from 2.5 V using a quenching resistor R76). If they are working properly, check the presence of these voltages at the terminals of IC U4: 2.5 V - pin. 14, 107, 126, 127; 1.8 V - pin. 55. If there is no voltage at one of the terminals, check the corresponding circuits from the stabilizers to the microcircuit.
If the supply voltage is normal, press the POWER button and monitor the change in the signal level at the pin. 52 or 53 U4. If there are no changes, check the serviceability of the button and the circuit from it to U4 (connected to the board via connector CN5). Then they check the external elements of U4 that ensure its operation: C48 (there should be a high potential at pin 72), Y1 (at pin 121, 122 a signal with a frequency of 12 MHz), memory chips U3 and U5 (they can only be checked by replacing them with serviceable ones). reference firmware). The last thing to check is the replacement of the MST726A TV processor itself.
If the network indicator does not light up when connecting the TV to the network, first check the adapter (presence of 12 V at the SG connector). Then, sequentially check fuse F1 (if it is open, check the filter capacitors and the input of the stabilizer U1 for a short circuit), the 5 V stabilizer U1. If the voltage at its output is zero, one of the external elements may be faulty: C13, C14, R1-R3, D1, L1. If they are working properly, replace the U1 microcircuit (analogous to MP1410 - ATC4060, only you need to connect pin 7 through a 100 kOhm resistor to 12 V).
The color image is distorted or one of the colors is missing
Check the signal range at the pin. 108, 110, 112 U4 - it must be at least 2.6 V. If there is no signal at one of the terminals, disconnect it from the LCD panel - unsolder the corresponding resistor (R38-R40). If a signal then appears at pin U4, the problem is in the LCD panel. Otherwise, replace the MST726A IC.
If the range of the output signals U4 is less than normal, check the power supply to U4 at the pin. 104 (1.8 V). If it does not meet the standard, check the stabilizer U11 (2.5 V) and elements L4, C25, C26. If the voltage at the pin. 104 U4 is normal, replace this chip.
There is no reception of TV programs, the TV works from the low-frequency input
Check for the presence of a PCTS with a swing of 1.7...2.3 V per pin. 20 U4. If there is a signal, the problem is in the Flash memory firmware or in the TV processor. If there is no signal or its range is significantly less than normal, check the elements of the radio channel. First of all, check the power supply of the elements:
5 V per pin 7 tuner and pin. 20 TDA9886TS. Power comes from stabilizer U1 through a switch on transistor Q1, controlled by the TUNER_PW signal from the pin. 62 U4.
12 V on capacitor ST16 (power supply for resonant amplifier QT3 LT4). Power comes from the network adapter through the QT4 QT5 key, controlled by the same TUNER_PW signal.
If the power supply is normal, disconnect the tuner output from the input of the resonant amplifier and apply an IF test signal with a swing of 60...100 μV here. If the test image does not appear on the screen, check the TDA9886TS chip and its external elements: SAW1, SAW2, Y2, QT1.
If there is a test image, check the tuner. If the control signals I2CSCL, I2CSDA, TUNER_AGC are present, replace the tuner.
There is a picture, but there is no sound or distorted
If there is no sound in all modes, the U7 audio amplifier (TDA7496) is most likely faulty. If the power supply (12 V on pins 15, 16) is normal, on pin. 5, 11 and 12 high potential (at least 2.5 V), touch the pin with a metal probe. 4 or 9 - the background sound of the household network should appear. If there is no sound, replace the IC.
If there is sound, but it is distorted, the TV system may be incorrectly detected - select SECAM/DK in the user menu. If this does not solve the problem, then there is a malfunction in the radio channel circuits. In this case (by sequential replacement), the SAW1 filter (K9453M) and the TDA9886 chip are checked.
There is no sound in one of the modes (TV signal reception or low-frequency input)
Check the operation of the sound switch U1: the presence of a corresponding signal at the input (pin 4, 11 - TV signal, pin 1, 2, 12, 15 - low-frequency input signals) and the output of the microcircuit (pin 3, 13). The switch control logic is shown in Table 2.
Table 2. 4052 Horn Switch Control Logic
No backlight (the image is barely visible in ambient light), there is sound
Check fuse F2 for open circuit. If it is faulty, use an ohmmeter to check for a short circuit the transistor assembly U12 and the primary windings of the transformer T1.
Then check the output connector CN19 for absence of charring of the contacts. If everything is normal, and the power supply does not work (no output voltage), replace the CCFL lamp with a 100 kOhm/2 W resistor and turn on the power. If the output voltage appears, the lamp is faulty, replace it. In another case, all elements in the secondary circuit of the source are checked and, first of all, the feedback circuit D14 R87 R88 C140.
If all elements of the source are in good condition, replace the U4 chip.
All missing diagrams can be downloaded.
Literature
1. N. Tyunin. Portable LCD TVs. Device and repair. - M.: SOLON-PRESS, 2008. (Series REPAIR, issue 111).
All DVB-T2 receivers, regardless of the name, are unified. The differences are mainly based on which of the two processors they are assembled on. Sometimes and rarely we encountered others; recently, set-top boxes with new brands of processors and their good performance and functionality have just appeared on sale. The differences between the set-top boxes are in the cost of the input tuner and the cost of the demodulator (the speed of channel switching greatly depends on this).
1.Processor - Mstar 7816(MSD7816). Outdated. For example, Rolsen RDB 508 is assembled on it; due to the processor, “braking” occurs when switching programs. Input tuner NMI 120 - low sensitivity. A classic example of a set-top box based on 1st generation circuitry - a device that is quite common in Lithuania and the Kaliningrad region and has a processor inside MSD7816(sometimes referred to in descriptions as LQFP128), NMI120 tuner and demodulator MSB1236C.
2. Processor - Ali 3812 - processor + demodulator in one package (which made it possible, with better characteristics, to reduce the cost of a set-top box assembled on the basis of the processor). Relatively fast channel switching, improved graphics and much more in comparison with Mstar 7816. Set-top boxes based on Ali 3812 can already record two programs simultaneously or watch one and record another (from one PLP). All receivers on the Ali 3812 have approximately the same menus and functionality, since they are determined by the processor.
3. Processor - Novatek 78316 - this already refers to us as the third type of processor, although, to the smallest approximation, it is similar to Ali 3812 in terms of speed and functionality. It does not have a built-in demodulator. One of the first tuners to appear on this processor is the Rolsen-RDB 507N. A review of the Rolsen-RDB507N has been published online.
Samples of set-top boxes based on the Ali 3812 processor: "Globo 60", "Globo 100", "Rolsen RDB513", "Rolsen RDB514" and others.
As a rule, they have a “second generation” input tuner:
Tuner MxL603 from MaxLinear Inc. - the latest, originally from California, the most protected from interference caused by modern communication networks 4G/LTE, Wi-Fi, MoCA and EoC., which is a serious main advantage of this tuner compared to the outdated NMI 120. Tuner MxL603 is universal, supports all digital satellite, terrestrial, cable standards, but is “cut down” in software to customer requirements at the product firmware level.
Now even newer MxL608 input tuners have appeared, the consoles on which we have not yet tested.
At the moment we have 5 models of set-top boxes in stock from 1300 to 2200 rubles, including Ali 3812 with tuners MxL603. Since there is demand, a batch of new ones will appear at the end of March, which we expect on the new processor Novatek 78316 and with the latest tuner MxL608.
Regarding prices. The cheapest thing that is sold everywhere is, as a rule, based on the Mstar 7816 processor + NMI 120 tuner.
Adding to the processor topic: There are also “exotic processors”. For example, our most expensive set-top box is assembled on a “cool” processor Ali3606, used, as a rule, only in rather complex, multifunctional satellite receivers. Plus, there is a multi-channel audio decoder AC3 (aka Dolby Digital) for using the set-top box as a player. Half of the films downloaded on the Internet have such a soundtrack. When connecting the set-top box via HDMI, you can use the internal decoder of the TV. When connecting via "bells" (RCA), the video will have no sound if the set-top box does not have such a decoder. This “thing” is licensed, so it significantly increases the cost of the set-top box.
MStar Semiconductor processors use external Flash memory to store program code. Computer monitors, budget TVs, DVRs and set-top boxes for receiving digital TV usually use a cheap 8-pin SPI-Flash IC as external memory. Of course, such a microcircuit can be written with a regular programmer. However, the question arises of obtaining the original dump, which was recorded in the chip before the damage, and repeated rewriting in order to select the most suitable firmware version. For example, the source of the original dump could be a device that cannot be opened (under warranty, etc.). In this case, the Postal hardware and software complex provides the ability to work in-circuit through available external VGA or HDMI connectors without opening the device.
General information
MStar Semiconductor produces a large number of specialized chips (System-On-Chip) for processing video signals. The purpose and internal composition of these chips can be very different, but there are common features that allow a unified approach to repair (meaning loading working software into Flash memory). In the following material, for simplicity, we will call all these complex chips “processor.”
Rice. 1. Appearance of the monitor board (TSUM processor same as MStar)
Despite storing code in external memory, MStar processors have internal read-only memory (ROM) containing debugging routines. In this sense, MStar chips are somewhat similar to chips from MediaTek (MStar is currently absorbed by MediaTek). However, between debug modes of processors
MediaTek and MStar there is a difference. MediaTek's proprietary chips have access to debug mode via a UART (standard low-voltage serial port) interface, while MStar chips, which originally had a simpler architecture, use UART as an extension of the earlier I2C-based debug mode. In fact, turning on the debug mode of MStar processors always occurs via the I2C protocol, and if necessary, UART is used in the future, and the same pins of the microcircuit are used for it (for some reason the developers found this convenient), so the contacts of the debug connector, if available, can be labeled Rx-Tx", although they also have the functions of the SCL-SDA buses of the I2C interface.
Rice. 2. VGA connector on the TV board (MStar processor under the radiator)
For in-circuit access to external (connected to the processor) SPI-Flash memory, it is enough to work using the I2C protocol, which is what our programmer uses. The processor for debugging mode has two addresses on the I2C bus, usually B2 and 92. The first address (B2) is intended for accessing registers and is used to stop the executing code and set the WP pin of the SPI-Flash IC high to a high level for further recording. The second address (92) is used exclusively to access the SPI-Flash. Through the first debug address, it is possible to access all internal registers of the processor, including setting the desired level on any pin; in fact, this is a kind of analogue of a JTAG interface. However, for repair purposes, it is only important to remove the write lock in Flash memory; sometimes this turns out to be impossible due to the closedness of the protocol and differences in connecting the WP SPI-Flash pin to the processor. However, reading memory is always possible, which allows you to easily read dumps necessary for repair from devices that cannot be opened.
Rice. 3. TV board based on the MStar processor, also having a VGA connector
To prevent accidental entry into debug mode, special words are used that are sent to the debug address first. This word is SERDB" for debugging and MSTAR" to enable the SPI-Flash interface. If someone uses a protocol analyzer, then the presence of these words in the data stream uniquely identifies the MStar processor.
The I2C protocol used by MStar processors in debug mode has errors in its implementation, which requires special hardware support, otherwise error-free in-circuit reading is almost impossible. The USB version of the programmer has a special Soft I2C mode adapted for MStar, which ensures unique reading accuracy. The LPT version of the programmer initially has automatic adaptation of the I2C protocol for MStar chips.
For most MStar processors, the programmer control program automatically initiates debugging mode by signature or uses the standard method for unknown processors. In general, it is enough to know: if the processor is of MStar origin, then the programmer will work with it.
Digital terrestrial television of the new DVB-T2 standard is increasingly gaining popularity. There are prerequisites for this. This is not only the widespread transition to digital broadcasting after 2015, but also high image quality, as well as expanding the capabilities of old TVs. Naturally, if you want to purchase this device, the question arises: “Which digital set-top box is better?” Let's figure it out.
Some time ago it was possible to rely mainly on 3 main chipsets:
- NTK78316 - chipset from Novatek, which has fast switching, but is not very stable and has poor sensitivity (comes with a demodulator);
- MSD7816 - MStar - an earlier model, but more reliable and more sensitive, although it has slow switching (comes with a demodulator);
- ALi M3812 is a more economical and cheaper solution. The processor and demodulator are combined in one package, which is cheaper than the MSD7816 + MSB1236 combination.
Now the list of chipsets on which the operation of DVB-T2 digital set-top boxes is based is much wider. Let's take for example the best Rolsen consoles of various models and their chipsets:
- RDB-507N - NTK78316, Novatek;
- RDB-602 - MSD7819 MStar;
- RDB-514 - Ali M3812.
At the same time, as you can see, even t2 set-top boxes from the same manufacturer have different circuit designs, since they are built on different microcircuits.
Characteristics
If you want to determine which set-top box for digital television is better based on its chipset, then it is useless to do this in a store. The seller probably won’t be able to tell you which IC the set-top box is assembled on, and there’s no such information in the passport. You need to search for such information on the Internet first.
Important characteristics of the chipset include:
- Changeover time per channel;
- Sensitivity.
You shouldn’t pay attention to the switching time, no matter what they say in the specifications, it will be approximately the same for all consoles, about 3 seconds. Low channel switching speed is a fairly pressing problem; it arises due to video encoding and decoding algorithms. Currently, home set-top boxes cannot instantly start displaying video images of digital channels immediately after they are turned on; it takes time, about 2-3 seconds, to stabilize data streams and start outputting video without distortion.
Well, as for sensitivity, it makes sense to pay attention to this parameter if you live very far from the tower, although it may be better to compensate for this by purchasing an antenna with high gain.
Options
It is much more important to determine which set-top box is better by the number of functions with which it is endowed. Options such as TVG - TV guide, Timeshift are not taken into account, since they are available on almost all models, but the presence of such options as:
- The presence of several connectors for connecting TVs with the obligatory presence of HDMI in order to watch in SD or HD quality;
- Control playback from the remote control (fast forward and backward, stop);
- Possibility of control from the front panel of the set-top box if the remote control is broken or lost.
The first set-top boxes were produced without an HDMI connector, which in itself is not very bad, since even through a low-frequency channel such as a SCART or “tulip” the video will be much better than when received by the TV itself. However, if you need to connect a large-diagonal LCD TV, then it is still better to have such a connector.
If you want to control playback to the beginning or end, and not watch a movie or listen to music from beginning to end in order, make sure that these control buttons are present on the remote control.
It is difficult to recommend any model, but some models can be given as examples. The DVB T2 KASKAD VA2102HD digital set-top box on the Mstar7816 chip has good sensitivity. Good set-top boxes with increased performance on the AliM3812 chipset: Oriel 740, Rolsen RDB-514.
Manufacturers
Here we can say that it is better to take a set-top box from a company that you trust or well-known brands Supra, Sony, Rolsen, Kaskad and so on. Against the backdrop of mass demand, many new manufacturers have appeared and the quality of their products is questionable.
It’s up to you to decide which digital set-top box you should buy, and I hope this article will help you begin to navigate them.
Happy shopping.
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