Technical description and composition of the DNS K42DS712 TV, panel type and modules used. The composition of the modules.DNS LED
Model: K42DS712
Panel: KPL-420B1LED4K
T-CON: LC470EUN-SFF1 P / N: 6870C-0432A; TL2354EP, TPS65178A, TPS65198, 416RP
LED driver (backlight): 35017884
PWM LED driver: iW7018-00, AP3041M-G
MOSFET LED driver: ME15N10-G
Power Supply (PSU): KPS-L110C3 34008454 35018155
PWM Power: FSL206MR, FAN7930, AS358BM
MOSFET Power: UK3568L
MainBoard: KDL42XS712AN-LGD-KD4 35017328
IC MainBoard: W25Q16B, H5TQ2G63GFR X2, GL852GC, THGBW565A1JBAIR, FR9887 X2, MSH9010-LF
Specifications K42DS712
DNS K42DS712
General recommendations for TV LCD LED repair
Possible malfunctions
- DNS K42DS712 does not turn on at all and does not show any signs of operability. Does not blink indicators and does not respond to control buttons.
In most cases, the KPS-L110C3 power supply module is faulty with similar manifestations. It is necessary to measure its secondary output voltages, and if they are absent, check the serviceability of the power switches (UK3568L) of the converters and rectifier diodes for a short circuit.
In the event of breakdowns in the secondary circuits, the converter can operate in a short-circuit mode, and in the event of a short circuit in the power elements of the primary circuit, the mains fuse is usually cut off.
Breakdown of Mos-Fet keys used in switching power supplies is often caused by malfunctions of other elements, for example, supply, frequency setting, damper ... as well as elements of Negative Feedback Stabilization. The PWM microcircuit (PWM) FSL206MR, FAN7930, AS358BM can also cause a malfunction of the power switch of the converter and is checked by replacement.
- There is no picture, but there is sound and reaction to commands from the remote control. Or the image appears immediately after switching on and disappears.
A malfunction is usually in these cases most likely in the backlight units of the display matrix. The reason for this may be an open circuit in the LED circuit, or a problem in stabilizing their power supply.
It is impossible to check the LED bars for a break without disassembling the panel with a multimeter or tester. For these purposes, it is necessary to open all series-connected PN junctions and a voltage of the order of tens of volts is required, and ideally a current source. Having disassembled the panel, it is necessary to check each LED separately. Chinese multimeters tend to light one 3-volt LED in the forward direction. In the case of using dual 6-volt LEDs, the PN junction of its protective zener diode can serve as an indicator of serviceability. In faulty LEDs, the 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 KDL42XS712AN-LGD-KD4 motherboard 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). In cases of complex MB (SSB) repairs and with the necessary skills and equipment, it may sometimes be necessary to replace its chips W25Q16B, H5TQ2G63GFR X2, GL852GC, THGBW565A1JBAIR, FR9887 X2, MSH9010-LF and other possible faulty components. Malfunctions associated with the use of BGA soldering technologies are usually easily diagnosed by the warm-up method.
Owners of the K42DS712 TV are recommended to contact only qualified specialists with the necessary experience for repair! Attempts to repair yourself without the appropriate knowledge and skills can lead to irreversible negative consequences!
DOWNLOAD FIRMWARE FOR SPI FLASH -----------> DNS K42DS712 , Main: KDL42XS712AN-LGD-KD4 35017328, Panel: KPL-420B1LED4K
DOWNLOAD SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> LED Driver iW7023-00
The appearance of the MainBoard KDL42XS712AN-LGD-KD4 is shown in the figure below:KDL42XS712AN-LGD-KD4
External view of the power supply
Main features of the DNS K42DS712 device:
Installed matrix (LED panel) KPL-420B1LED4K.
Matrix control uses a Timing Controller (T-CON) LC470EUN-SFF1.
The LED driver 35017884 is used to power the backlight LEDs, it is controlled by the iW7018-00, AP3041M-G PWM controller. The keys of the ME15N10-G type are used as power elements of the LED driver.
The formation of the necessary supply voltages for all nodes of the DNS K42DS712 TV is carried out by the KPS-L110C3 power module, or its analogs using FSL206MR, FAN7930, AS358BM microcircuits and power switches of the UK3568L type.
MainBoard - the main board (motherboard) is a KDL42XS712AN-LGD-KD4 module, using W25Q16B, H5TQ2G63GFR X2, GL852GC, THGBW565A1JBAIR, FR9887 X2, MSH9010-LF and others.
DNS TV K42DS712 with LCD KPL-420B1LED4K, 42 "(107 cm) diagonal in 16: 9 format. The required screen brightness of 350 cd / m2 is provided by LED backlighting. Contrast - the ratio of maximum brightness to minimum brightness is 1200: 1. This model uses a panel with backlight LEDs - Edge LED.
There is support for 3D images using passive polarization technology.
The KPL-420B1LED4K matrix and the MainBoard KDL42XS712AN-LGD-KD4 software provide viewing of broadcasts and movies in high quality HD at a resolution of 1920x1080 pixels in graphics resolution at 1080p (Full HD).
K42DS712 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 standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p. 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-L110C3 power supply.
Dimensions: With stand 957x622x250 mm, Without stand 957x566x55 mm.
TV weight: 15.6 kg.
Attention! The KPL-420B1LED4K panel of the DNS K42DS712 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.