Tuesday 10 March 2020

REPAIR / SERVICING TV SONY KD-49XE7077


Technical description and composition of the SONY KD-49XE7077 TV, panel type and applicable modules. The composition of the modules.
SONY LED
Model: KD-49XE7077
Chassis / Version: BB8 1-981-926-21
Panel: YS7S490HNG01
LED backlight: LB49013 V0_00 4-595-781 70526GD 77900 DFD-8
T-CON: 6870C-0726A
LED driver (backlight): 1-981-457-12 173638812
PWM LED driver: BD9423EFV
Power Supply (PSU): ACDP-120E02 Adapter 19.5V 120W
MainBoard: 1-981-926-21 173657421 A2182751B
IC MainBoard: CPU: MT5597BMEJ, EMMC: THGBMOG5D1LBAIL
Tuner: CE251ZP
Technical Specifications KD-49XE7077
SONY KD-49XE7077
General repair guidelines for TV LCD LED
Possible manifestations of defects
- SONY KD-49XE7077 does not turn on and does not show any signs of performance at all. Does not blink indicators and does not respond to control buttons.
In some of these cases, a malfunction is detected in the ACDP-120E02 power supply module.
The owner of a TV set usually acquires an external power source such as ACDP-120E02 Adapter 19.5V 120W on its own, it often happens that its repair is impractical, but the simplest defects typical of IIPS can be seen and easily fixed after opening. It is necessary to measure its output voltages, and in case of their absence, check the operability of the power switches of the converters and rectifier diodes for the probability of short circuit.
In case of any breakdowns in the secondary circuits, the converter can operate in emergency short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse or the current sensor at the source of the key more often breaks.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements that can put it out of operation in key mode or provoke the excess of maximum current or voltage values. These can be circuits supplying the PWM controller, damping or frequency-setting circuits, or elements of OOS (negative feedback) in the stabilization circuit. PWM controllers (PWM), in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- There is no image, but there is sound and reaction to commands from the remote control. Or the image appears immediately after turning on and disappears.
In most of these cases, a malfunction is detected in the nodes and backlight elements of the LED panel. More often the reason for this is the breakdown of the LEDs, or poor contact in the connectors of the strips, less often the LED driver may be malfunctioning.
To check the health in the LED circuit, it is better to use a current source with a maximum voltage of 200V. We do not recommend using any voltage sources for this purpose. You can check each LED individually with a simple Chinese multimeter (powered by 9 volts) in the P-N-junction test mode. If you connect the red probe of the multimeter to the anode of the LED, and the black to its cathode, then the 3-volt LED will light up slightly, and in the opposite direction you can detect the transition of the emergency zener diode. A zener diode PN junction indirectly indicates a LED-a
- 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 1-981-926-21 should begin by checking the stabilizers and power converters needed to power the microcircuit and matrix. If necessary, update or replace the software (software). Sophisticated MB board repair (SSB) is in some cases possible and practiced by repairmen. To do this, check and, if necessary, replace the CPU elements: MT5597BMEJ, EMMC: THGBMOG5D1LBAIL. BGA chip malfunctions are usually easy to detect by warming up.
If the TV works normally from external devices, but does not tune into television channels, the CE251ZP tuner may be malfunctioning. In such cases, first of all, you should make sure that there are supply voltages at its corresponding conclusions. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus. Sometimes the cause of the inoperability of the tuner may be a software failure.
Owners and users of the SONY KD-49XE7077 TV should remember that self-repair without special knowledge, skills and qualifications can be fraught with negative consequences that can lead to complete non-repairability of the device!



The appearance of MainBoard 1-981-926-21 is shown in the figure below:
1-981-926-21
The appearance of the power supply
Main features of the device SONY KD-49XE7077:
Installed matrix (LED panel) YS7S490HNG01.
The matrix control uses the Timing Controller (T-CON) 6870C-0726A.
The LED driver 1-981-457-12 is used to power the backlight LEDs, it is controlled by the BD9423EFV PWM controller.
To power all the internal components of the SONY KD-49XE7077 TV, an external source such as ACDP-120E02 Adapter 19.5V 120W is used.
MainBoard - the main board (motherboard) is a module 1-981-926-21, using CPU chips: MT5597BMEJ, EMMC: THGBMOG5D1LBAIL and others.
The CE251ZP tuner provides TV reception and channel tuning.

Trademark: SONY, Model: KD-49XE7077.
Briefly from the TV: LCD, LED backlight, 48.5 ", 3840x2160, 4K UHD, HDR, TFT IPS, DVR, there is a satellite tuner, sound: 20W, HDMI: 3, Internet access, Wi-Fi, Smart TV.
On the official site of Sony there is firmware (Firmware) - updating the software to version v8.764 from 11/21/2018.
The composition uses MainBoard 1-981-926-21 173657421 A2182751B and LCD-panel YS7S490HNG01.
Power supply unit external ACDP-120E02 Adapter 19.5V 120W.
SONY KD-49XE7077 TV with YS7S490HNG01 LCD, 48.5 "(123 cm) diagonal size 16: 9 format. This model uses side backlighting from Edge LEDs.

The YS7S490HNG01 display and software (software) of the 1-981-926-21 board provide for 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-49XE7077 TV has built-in SMART Software and preinstalled Opera TV Operating System. Connecting to the Internet can be done via Wi-Fi. Video processor supported multimedia file formats: MP3, WMA, MPEG4, HEVC (H.265), Xvid, DivX, 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, HDMI x3, USB x3, Ethernet (RJ-45), Wi-Fi 802.11n, WiDi, 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 120 watts.
Overall dimensions: with stand 1102x744x160 mm, without stand 1102x646x70 mm.
TV Weight: with stand: 12.1 kg, without stand: 11.4 kg.
Attention! The YS7S490HNG01 panel of the SONY KD-49XE7077 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.