What is the wisdom screen? Cool open glory A55 detailed review

A55 such a high-strength TV, in the end the value is not worth 6,999 yuan? How is the quality of work? In an earlier disassemble article A55, I initially demonstrated the A55 mysterious "internal world." Today, I will take a more in-depth dismantling and interpretation of the cool open A55 glory, let everyone look at the A55 from a more professional point of view!

Show A55 backplane with no interface, is it more sexy than the ordinary black backplane?

In the previous article on the simple disassembly, the internal circuit of the A55 has been briefly introduced, and then the details of these circuits will be studied.

Next, I will follow the order of the PCB circuit in the figure above, namely power supply -> backlight drive -> motherboard -> display control module -> wireless expansion module -> speaker -> display screen, in a professional perspective One for everyone.

One: Visible quality, A55 power analysis
This circuit board is the power conversion module of the A55 and is the strong heart of the A55. The power supply is accessed from the lower left standard interface, and through a series of complicated processes such as rectification, filtering, frequency conversion, and voltage regulation, the voltage and current required by the lower-level circuit are finally obtained.
As a non-electronic professional Xiao Bian, trying to understand the principle of this circuit is not easy, and instantly feel the lack of knowledge. However, I also felt relieved when I thought about it. As long as the product is easy to use, it would not be a problem.... Although I say this, I still want to use the components of the A55 circuit to take a look at the cool opening. "What is the attitude of the siege lion" to design the A55?

First, beside the power input jack, you can see there is a small brown column, which is the most basic protection component in the A55 circuit - the fuse. Its role is that when the circuit is abnormal when the current is too large, the circuit will be cut off and the protection circuit won't be burned if the current is too high. And next to the fuse is a green patch that is a "smart" element called the thermistor, which is numbered SCK208. Its main function is to suppress the surge current at the moment of starting. Because at the instant of power-on, the voltage across many capacitors is zero, and it is in a path state. There will be a lot more inrush current than normal at the instant of power-on. This thermistor can increase the resistance through the heat when the current is high. The large current suppresses the reduction and also reaches the protective circuit. Digression, a lot of electrical appliances in the frequent after the switch, the life expectancy is reduced, it is likely that the use of a relatively poor thermistor or simply useless.

In addition, in the power circuit board, it is worth noting that the brown elongated strip of electrolytic capacitors, which is from the well-known Japanese brand Black King KXJ series. Black King Kong capacitance is not simple, look at a group of market share data:
1. Black King Kong, accounting for 22% of the world
2, nichcon, accounting for 17% of the world
3, ruby, accounting for 13-14% of the world
Panasonic, accounting for 10% of the world
Ah, the capacitance in the world today is a good Japanese brand. The Chinese must work hard!
Black King Kong, also known as Jia Meigong, English name is chemi-con, quality and performance are very good, technical advantages, of course, the price is very high, almost all the most expensive conventional capacitors. It has done a good job in discharging capacitors, aluminum electrolytic capacitors, and thin desert capacitors. The main customers include Amesco, Asus, Delta, Skyworth, and some other Chinese military product manufacturers. The specific names should not be disclosed.
II: LED backlight power driver circuit: stability overwhelming
Immediately after entering the backlight driver circuit module, the main function of this module is to provide constant current and constant voltage power to the LED backlight in the display screen. LED is actually a light emitting diode light source. Unlike a conventional light source, it is a non-linear component. The function of this circuit is to dynamically adjust the power supply state through various feedbacks, so that the current tends to be constant. A simple description of the human language is: LED backlight is a good thing, but bad-tempered, poor service on the emotional changes, work instability. So design a circuit specifically to wait for it.

The PCB board is surrounded by three lines, and the power conversion circuit is connected to the left, the LED light source in the display screen is connected, and the intelligent processor main board is connected to the right.

Three: Luxury configuration of the processor board - A55 wisdom brain

OK, then this component module can be important, is the brain of the A55 - intelligent processor board! Look at the map, the middle part of the middle of the motherboard is covered with a metal heat sink, if not guessed, it is Huawei. Hass owns a high-performance SoC chip with independent intellectual property rights - Hass Hi3751 V800, which will be announced soon!

There are a few things that are worth noting about the intelligent processor board. The first is that this motherboard is covered with a lot of solid capacitors (components with red icons). It should be noted that whether or not solid capacitors are used in electrical products has now become an important standard for measuring the quality of a product. The solid-state capacitor is called a solid-state aluminum electrolytic capacitor and is the highest-end capacitor except the tantalum capacitor. It uses a high-conductivity molecular material to ensure the performance while also reducing the volume, and is different from the traditional electrolytic capacitor filled with electrolyte. The solid-state capacitors used in solid-state capacitors are not very sensitive to temperature, and do not produce dangerous situations such as bursts, leaks, etc. The stability in terms of high and low temperature and performance is even more outstanding.

In addition, the black PCB board used by the A55 is mentioned here again. The black PCB is generally only found on high-end devices such as Apple computers. In the process of making a PCB, black is the most likely to cause chromatic aberration. If the raw materials used and the manufacturing process are slightly deviated, it will directly lead to an increase in the defective rate and increase the production cost. Secondly, because the circuit traces of the black PCB are difficult to identify, it will increase the difficulty of repair and debugging in the R&D and after-sales phases. Generally, if there is no deep R&D design team, it will not be easy to use the black PCB. It can be said that using a black PCB is a sign of a strong brand of self-confidence.

Afterwards, it took a lot of effort and finally revealed the heat sink on the motherboard (please do not imitate it). Sure enough, HiSilicon Hi3751 V800 reveals its true colors! This chip is based on quad-core Cortex-A9 CPU + eight-core Mali-450 GPU + dual-core Hi-VEngine VPU, a total of fourteen cores, and CPU single-core up to 1.5GHz , is the most powerful TV chip on the market. Combining the lightweight optimization technology of Linux with Coocaa's lightweight system, the A55 is faster and faster than ordinary Internet TV in daily startup, response, high-definition video, and large-scale game applications.

In addition, A55 built four HYNIX (Hynix) DDR3 memory, model H5TQ4G63AFR, a total capacity of 2GB capacity, frequency up to 1866MHz, dual channel specifications can bring 2 times the memory bandwidth, in a large number of data exchange processing can be Bring faster speeds. Hynix is ​​one of the largest memory brands in the world, accounting for 30% of market share in 2013. Hynix's memory is very good and its quality is guaranteed. These memory chips have a high frequency and run fast.

Compared with the 2G or 4G storage capacity of many smart TVs, the A55's capacity is also luxurious. A 16GB Toshiba THGBM5G7A2JBAIR EMMC Flash memory chip was used on the motherboard, using a 19nm process. This kind of flash read and write performance is outstanding, and the system startup speed, application installation speed, loading speed, and photo file browsing speed are all significantly improved. This is also one of the important reasons for guaranteeing the A55 speed.

On the A55 processor motherboard, in addition to a variety of luxurious chips and components, I also found a chip covered with a ceramic heat sink. This is what it is. Take a look at this heat sink:

Below the heat sink is the TAS5707 from Texas Instruments (TI), a 20-watt digital stereo audio power amplifier chip with EQ and DRC (software control). The TAS5707 supports 8kHz to 48kHz sampling frequency, can provide 20W power to 8 ohm audio load, TAS5707 operates from 8V to 24V, can drive bridge-connected stereo speakers, analog audio input/output. What is the concept of 20W? Take a look at the maximum decibel data tested:

107.3 dB, what is the concept? 110 dB: propeller plane take-off sound; 100 dB: pressure drill rig sound; 90 dB: noisy bar ambient sound. Judging yourself, ha.

Oh, back to the ceramic heat sink, why not use the traditional metal cooling it? A55's audio amplification chip power, heat is a challenge. Ceramic fins have the advantage of small heat capacity, do not accumulate heat, and do not form a "hot ladder" like metal fins affect heat dissipation; the biggest feature is the structure of the micro-holes in the ceramic itself, which greatly increases the heat dissipation in contact with the air. Area, greatly enhance the cooling effect, the same conditions, in the natural convection state, heat dissipation than copper, aluminum, closed environment, active radiation heat dissipation capacity of 8.8 times the metal material, the heat is more obvious advantages.
After reading the front side of the intelligent processor main board, looking through the back to see, a very clean board, while the middle area is a dense and regular component pins and solder joints.

Four: 4K IPS Display Core - LGD Unknown Chip
Then look at the A55's LCD screen driver circuit, using the LCD driver screen with LG OEM driver board, liquid crystal driver control chip model TLi2380EP. According to the cool open official introduction, A55's original LGD 4K screen can use chip adaptive video coding algorithm to achieve 4K image point-to-point restore, improve the refresh rate, effectively solve the traditional 4K TV motion picture jitter, tailing problem, estimated with this LCD Driving a master chip has a lot to do with it.

V: Wireless Data Exchange Module - Unlimited Secrets

The biggest difference between the cool open A55 glory is to use wireless to complete all operations. The wireless technology module, on the A55, can be said to be a more important circuit than the main control chip. During the dismantling time, we discovered that the original A55 had multiple pieces of wireless interaction module circuits with different divisions of labor, including Wi-Fi, Bluetooth and 2.4G human-computer interaction, wireless HDMI, etc., and we explained them one by one.

The first is the 2.4GHz human-computer interaction module. Unlike the imagination, the A55 actually supports almost all 2.4G wireless protocols. In other words, in the remote control of human-computer interaction, control of television and content, there are only unimaginable control methods and equipment that cannot be implemented. These features made my A55 impression change again. If I'm an engineer, I can make all the live devices in the house interact with the A55! This is a good thing to burn!

The A55's 2.4G human-computer interaction module consists of multiple chips:
Look, the biggest one is Nano's WN6102, which is a highly integrated system-on-chip for human-computer interaction/wireless audio, based on the high-performance CPU core CK610E, based on AMBA bus architecture, integrated I2S/SPDIF, SPI, UART, I2C, PCM, SDIO, GPIO, PWM, PCM, USB, ADC and other peripherals, support AUDIO acceleration, FEC error correction, CRC check and RSA encryption, and integrate SRAM, OTP and ROM.

In addition to WN6102, there are CC2590 and FRE004 chips around the world's leading semiconductor company TI. Take the TI CC2590 as an example. This chip is a low-power, low-voltage, high-performance 2.4GHz RF front-end with output power up to 14dBm (25mW) and integrated internally. Switches, matching networks, Balun transformers, LNAs, power amplifiers, and inductors operate from 2.0V to 3.6V and are available for all 2.4GHz ISM band systems, wireless sensor networks, and more.

Here we briefly introduce the 2.4GHz wireless technology, which is a short-range wireless transmission technology, for open source use, with strong versatility, high bandwidth, strong anti-interference, transmission distance and many other advantages. Cool open glory A55 has a powerful wireless function, 2.4GHz human-computer interaction module contributed. With the 2.4GHz human-to-machine interaction module, the A55 can easily connect with a variety of wireless devices such as gamepads and wireless mice. In the increasingly hot smart home era, the A55's 2.4GHz wireless capabilities clearly have more exciting possibilities.
A55's Wi-Fi module uses Realtek's RTL8812AU chip, supports 2.4GHz and 5GHz dual-band dual-antenna Wi-Fi, dual-receive dual-fire, support 802.11ac 2T2R, theoretical networking transceiver speed to Gigabit, which is the future Wi- Fi's mainstream. What N, what G. Prepare to be eliminated.
CSR8510 is A55's Bluetooth module, supports USB full-speed compatibility, supports Bluetooth 4.0, and is backward-compatible, can be used with other Bluetooth+ wireless network module combinations, and other RF operating together. With this module, the A55 can easily connect with Bluetooth speakers, watches, headphones, microphones, and Bluetooth game controllers, making the TV more powerful!

Although the A55 is designed with no interface, the A55 is actually equipped with two interfaces at the bottom, but it is only hidden. A USB project interface is only used for system upgrade of the system mode; another HDMI interface needs to be used with the A55's wireless HDMI receiver/transmitter (optional).
The picture above is the optional A55 wireless HDMI receiver/transmitter. The A55 can be said to further implement the essence of “wireless” through the built-in WiHD 60GHz wireless HDMI module. A55 through the wireless HDMI receiver / transmitter's four HDMI interface, free wireless connection PS4, set-top boxes and other devices, and as long as the HDMI cable is inserted, A55 can automatically identify and quickly switch the signal source, very smart.

A55's button module can be seen inside the "MOK1" sign is the infrared receiver, it can be seen that although the A55 does not have a remote control, it can actually support! Infrared receiver is next to the switch display LED lights, red , blue, purple, etc., are displayed through the light guide band.

Six: Not a simple speaker system - multi-speaker sound cavity
Next, we will introduce the audio unit. From the beginning, we can see that the A55 slim fuselage accommodates two small black sound chambers. Each sound chamber is equipped with a tweeter at the bottom. A large stroke bass speaker.

On the other side of the sound cavity is covered with a large area of ​​sponge layer, responsible for absorbing the resonance and standing wave of the speaker, so that the sound is more pure and natural! The A55 is matched with the bass speaker and the tweeter, which is rich in sound and strong in performance; the tweeter Through scientific design, the characteristics of high notes are highlighted.

According to the Cool Open official, the A55 is selecting the largest and best sound module for the sound cavity within the allowable range of volume to ensure good sound quality. A55 also supports DTS 2.0 certification, Dolby Digital Plus Dolby decoding and DTS TruSurround surround sound, with dual-channel stereo four-speaker combination to create stunning audio and video, really enough to force!

Seven: The original LG Display display screen - 55 inch 4K IPS

Next to introduce the A55's LCD screen, first look at the label, model is LC550EGY-SHM1, a 55-inch original LGD 4K IPS hard screen, check its specifications on the Internet.

A55 display angle test, the color performance in the upper and lower left and right are relatively good

This original LGD 4KIPS hard screen contrast ratio of up to 1200:1, stronger picture performance, support for 10bit display, wider color gamut, 9ms response time, faster response, and also has 178 ° wide viewing angle display, it should be said The screen brightness, viewing angle and response time have obvious advantages.

Eight: to add some interesting details

Finally, look at the A55's other internal materials and process details. In addition to the black PCB mentioned earlier, the A55's cable is also very unique.

Cool open glory A55's cables are covered with a layer of metal shielding, in addition to more beautiful, the most important thing is to prevent signals from interfering with each other, high stability.

There is also the A55's internal steel plate there are several bold large screw hole seat, used when wall-mounted, very strong, people look very safe.

Finally, look at the rear shell of the A55. The back shell of A55 is painted with electroplating silver paint. The electroplating silver paste and resin are made of imported materials. The price of 1 kilogram of electroplated silver paste is similar to that of an iPhone 5s! The electroplated silver paint is generally used in the high-end automobile spraying industry, and the A55 uses electroplating. Silver paint printing, in the reduction of the weight of the entire machine while having a metal texture, a more stylish sense of technology.
Finally ended the disassemble with an official back view. OK, everyone, I'm going to start installing the A55. See you later.

Summary: Smart Screen, unlimited imagination

In general, the cool open glory A55 uses a rather high-end high-end configuration, using a large number of imported components, pay attention to the details of the process, with a high degree of integration and high modularity of the internal structure. Should say a penny and goods, Cool open glory A55 price 6999 yuan, but also value for money. In the current promotion of the A55's promotional materials, there are not many parameters related to wireless, such as Bluetooth, 2.4G interaction, etc. Through this disassemble, I have discovered many secrets that we do not know. About wireless, A55 gave me too much room for imagination. And it is theoretically very easy to implement. It seems that the term "smart screen" is more and more suitable for the A55. However, do I know too much?