Tuesday 10 March 2020

REPAIR / SERVICING TV SONY KD-43XE8077

Technical description and composition of the SONY KD-43XE8077 TV, panel type and applicable modules. The composition of the modules.
SONY LED
Model: KD-43XE8077
Chassis / Version: BFX 1-981-326-12
Panel: LC430EQY (SK) (A1) // YM7S430HNG01
LED backlight: NLAW20450 E_R411107817F43F00213NJ
T-CON: 6870C-0704A 6871L-4875B
LED driver (backlight): 1-981-457-11 (173638811)
Power Supply (PSU): Adapter AC / DC 19.5V
MainBoard: 1-981-326-12 (173633712)
IC MainBoard: CPU, NAND Flash, Audio
Tuner: CE551ZP
Technical Specifications KD-43XE8077
SONY KD-43XE8077
General repair guidelines for TV LCD LED
Possible malfunctions
- The SONY KD-43XE8077 TV does not turn on and does not show any signs of operability at all. There is no reaction to the remote control and control buttons from the front panel.
With such manifestations, in some cases, the Adapter power module is faulty.
The owner of the TV can purchase an external power supply adapter type AC / DC 19.5V independently and its repair is not always advisable. In any case, the simplest typical defects characteristic of most IIP schemes can be easily detected and eliminated after opening. It is then necessary to measure its output voltages and, if they are absent, you should check the power switches and rectifier diodes of the converters for the probability of a short circuit.
In case of diode breakdowns in the secondary circuits, the converter can operate in emergency short-circuit mode without output voltages, and during short circuit in the power elements of the primary circuit, the mains fuse and / or current sensor at the source of the key usually breaks.
Mos-Fet power switches, used in switching power supplies, sometimes fail due to a malfunction of any other elements that can put it out of operation in key mode or create an excess of the maximum permissible parameters of the switch. These can be elements supplying the PWM controller, frequency-setting or damping circuits, or negative feedback elements in the stabilization circuit. PWM controllers, in the absence of visible damage or explicit short-circuit between the terminals, are checked by replacing with new ones, or obviously working.
- There is no image, but there is sound and reaction to the remote control. Or for a second, the image may appear immediately after switching on.
Often in such cases, there is no LED backlight. Often the cause is a malfunction of the LEDs (open circuit, short circuit ...), or the connectors of the strips (strings), less often the LED driver is malfunctioning.
It is impossible to detect a break in the LED line without disassembling the panel with a simple multimeter. The LEDs are connected in series and to open their transitions, a voltage of several tens of volts is required. Ideally, a current source is suitable for such purposes. You can open the panel and check each LED separately. Typically, Chinese multimeters light up a single 3-volt LED, if you connect the probes in the forward direction to it (red probe to the anode, black to the cathode). In dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of health. In the event of a LED malfunction, its zener diode will either be cut off or broken into short-circuit.
- The indicator on the front panel blinks, the TV does not turn on in the operating mode, it does not respond to the remote control.
Repair or diagnostics of the motherboard 1-981-326-12 should begin by checking the stabilizers and power converters needed to power the microcircuit and matrix. If necessary, update or replace the software (software). When repairing an MB board, you need to check its components CPU, NAND Flash, Audio. Defective items should be replaced. If chips with BGA soldering technology are used, a problem in its implementation is detected by the local heating of the chip.
If there is no reception of television channels, but the TV is working properly from external devices, first of all you need to check the voltage of the CE551ZP tuner and update the software. The pulses from the I2C bus must be controlled with an oscilloscope.
It should be remembered! Attempts to self-repair a SONY KD-43XE8077 TV, in the absence of the necessary qualifications and experience, are categorically not recommended and are fraught with negative consequences, up to the complete non-repairability of the device!


On the official site of Sony there is firmware (Firmware) - a software update to version 6.6520 from 06/30/2019.
The appearance of MainBoard 1-981-326-12 is shown in the figure below:
1-981-326-12
Main features of the device SONY KD-43XE8077:
Installed matrix (LED-panel) LC430EQY (SK) (A1) or YM7S430HNG01.
The matrix control uses the Timing Controller (T-CON) 6870C-0704A.
The LED driver 1-981-457-11 is used to power the backlight LEDs.
To power all the internal components of the SONY KD-43XE8077 TV, an external adapter type AC / DC 19.5V is used.
MainBoard - the main board (motherboard) is a module 1-981-326-12, with the use of CPU chips, NAND Flash, Audio and others.
The CE551ZP tuner provides TV reception and channel tuning.

SONY KD-43XE8077 TV with LC430EQY LCD, 42.5 "(108 cm) diagonal display in 16: 9 format. This model uses side illumination from Edge LEDs.
The LC430EQY display and software (software) of the 1-981-326-12 board provide viewing in high quality UHD 4K at a resolution of 3840x2160 pixels in the 4K UHD, HDR standard. Image processing is performed using modern High Dynamic Range (HDR) technologies with an extended range of brightness gradations.
The KD-43XE8077 TV has built-in SMART Software and a pre-installed Android Operating System. Connecting to the Internet can be done via Wi-Fi. Video processor supported media file formats: MP3, WMA, MPEG4, HEVC (H.265), Xvid, MKV, JPEG.
The power of the sound speaker system 20 W (2x10 W) is provided by two speakers. It uses a NICAM stereo signal processing system and Sound Surround.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV x2, component, HDMI x4, USB x3, Ethernet (RJ-45), Bluetooth, Wi-Fi 802.11ac, Miracast. An output for connecting headphones is provided.
The digital tuner is capable of receiving television channels in the standards DVB-T MPEG4, DVB-C, DVB-T2, DVB-S2.
The power consumed by the TV in the operating mode from the network is 133 watts.
Overall dimensions: with stand 964x617x242 mm, without stand 964x567x57 mm.
TV Weight: with stand: 10.8 kg, without stand: 10.1 kg.
Attention! The LC430EQY (SK) (A1) panel of the SONY KD-43XE8077 LED TV is its most expensive element.
Avoid hitting the glass and excessive pressure on the screen surface to avoid damage to the LED panel!
It is unsafe to get any liquid on the screen. Sometimes one drop of water is enough, if it flows down the glass onto the cables, the TV can become unrepairable.