Technical description and composition of the DNS K55DS712 TV, panel type and modules used. The composition of the modules.DNS LED
Model: K55DS712
Chassis / Version: 35017841
Panel: HV550WUP-200
T-CON: 6870C-0444A LC470DUE-SFR1
LED driver (backlight): V323-F01 // 35017905 34010044 REV-00
PWM LED driver: IW7018-00
Power Supply (PSU): 35017862 34010004 KPS + L150C3
PWM Power: FSL206MP, NCP1397BG, NCP1608
MainBoard: 35017841
IC MainBoard: CPU: MSD6369IV, SPI FLASH: W25Q16V, AUDIO: RT9108NB
Tuner: MXL601
Specifications K55DS712
DNS K55DS712
General recommendations for TV LCD LED repair
Possible malfunctions
- DNS K55DS712 does not turn on and does not show any signs of operability at all. Does not blink indicators and does not respond to control buttons.
In some of these cases, the main switching power supply, module 35017862, turns out to be faulty. Its output voltages should be measured, and in their absence, check the serviceability of the power switches of the converters and rectifier diodes for the probability of a short circuit.
In case of any breakdowns in the secondary circuits, the converter can operate in an emergency mode of a short circuit, and with a short circuit in the power elements of the primary circuit, the mains fuse or the current sensor at the source of the key often breaks off.
The breakdown of power switches (MosFet) in switching sources is sometimes caused by malfunctions of other circuit elements, for example, in the circuits supplying the PWM controller, frequency setting or damper, as well as in the circuits of Negative Feedback (OOS) stabilization. PWM controllers (PWM) FSL206MP, NCP1397BG, NCP1608, if they do not have visible damage to the case and an open short circuit between the pins, are usually checked by replacing.
- There is no picture, but there is sound and all other functions work. Sometimes when you turn it on, the image appears and disappears for a second.
As a rule, in such cases there is no display backlight. The reason can sometimes be in the power supply of the LEDs, but more often in their malfunction (breakdown or breakage), sometimes in the violation of the contact connections of the LED strips.
It is impossible to detect an open circuit in the LED line without disassembling the panel with a simple multimeter. The LEDs are connected in series and a voltage of several tens of volts is required to open their junctions. Ideally, a current source is suitable for such purposes. You can open the panel and check each LED separately. Usually, Chinese multimeters lightly light up one 3-volt LED if you connect the probes to it in the forward direction (red probe to the anode, black to the cathode). For dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of the LED health. In the event of a malfunction of the LED, its zener diode will either be cut off or pierced in the K / Z.
- The indicator blinks or is on constantly, the TV does not turn on, does not respond to the remote control.
Repair or diagnostics of the motherboard 35017841 should begin with checking the stabilizers and power converters necessary to power the microcircuits and matrix. If necessary, you should update or replace the software (software). If it is not possible to replace the MB (SSB) board, you must check the serviceability of its elements - CPU: MSD6369IV, SPI FLASH: W25Q16V, AUDIO: RT9108NB. Defective components must be replaced.
If the TV operates normally from external devices but does not tune to TV channels, the MXL601 tuner may be faulty. In such cases, first of all, you should make sure that there are supply voltages at its corresponding terminals. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus. Sometimes the reason for the inoperability of the tuner may be a software failure.
We remind users again! Attempts to repair the DNS K55DS712 TV on your own without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!
DOWNLOAD FIRMWARE FOR SPI FLASH -----------> DNS K55DS712, Main: 35017841, Panel: KPL+550B1LED3K
DOWNLOAD FIRMWARE FOR SPI FLASH -----------> DNS K55DS712, Main: 35017841, Panel: HV550WUP-200
The appearance of MainBoard 35017841 is shown in the figure below:35017841
Main features of the DNS K55DS712 device:
Installed matrix (LED panel) HV550WUP-200.
Matrix control uses Timing Controller (T-CON) 6870C-0444A.
The LED driver V323-F01 is used to power the backlight LEDs and is controlled by the PWM controller IW7018-00.
The formation of the necessary supply voltages for all nodes of the DNS K55DS712 TV is carried out by the power module 35017862, or its analogs using FSL206MP, NCP1397BG, NCP1608 microcircuits.
MainBoard - the main board (motherboard) is a 35017841 module, using CPU chips: MSD6369IV, SPI FLASH: W25Q16V, AUDIO: RT9108NB and others.
The MXL601 tuner provides TV reception and channel tuning.
DNS TV K55DS712 with LCD HV550WUP-200, diagonal 55 "(140 cm) 16: 9. The required brightness of the screen of 350 cd / m2 is provided by LED backlighting. Contrast - the ratio of maximum to minimum brightness is 1200: 1. This model uses a panel with an edge LED backlight - Edge LED.
There is support for 3D images using passive polarization technology.
The HV550WUP-200 B4 matrix and MainBoard 35017841 software provide viewing of broadcasts and movies in high quality HD at a resolution of 1920x1080 pixels in graphics resolution at 1080p (Full HD).
K55DS712 has built-in SMART software and pre-installed Android operating system. Internet connection can be made via Wi-Fi wireless connection. The input high-frequency or video signal is decoded in analog systems PAL, SECAM, NTSC. Graphic processing and formation of a digital signal occurs in the 480i, 480p, 576i, 576p, 720p, 1080i, 1080p standards. Supported media file formats: MP3, WMA, MPEG4, DivX, MKV, JPEG.
Speaker power 20 W (2x10 W) is provided by two speakers. The NICAM STEREO audio processing system is used.
External interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, audio x2, component, VGA, HDMI x4, MHL, USB x3, Ethernet (RJ-45), Wi-Fi. A headphone output is provided. To connect a computer or laptop to this TV model, use the VGA (D-Sub 15) connector on the TV case, this interface supports resolutions: 640x480, 800x600, 1360x768, 1920x1080. The digital tuner is capable of receiving TV channels in DVB-T standards.
The TV uses a KPS + L150C3 power supply.
Dimensions: With stand 1242x779x275 mm, Without stand 1242x726x55 mm.
TV weight: 23.4 kg.
Attention! The HV550WUP-200 B4 panel of the DNS K55DS712 LED TV is an expensive and unreliable element.
Do not allow any impact on the glass and pressure on the screen surface to avoid damage to the LED panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it drips down the glass onto the cables to make the TV unrepairable.