Tuesday 10 March 2020

REPAIR / SERVICING TV SONY KD-55XE7077

Technical description and composition of the SONY KD-55XE7077 TV, panel type and applicable modules. The composition of the modules.
SONY LED
Model: KD-55XE7077
Panel: V550QWSE06
LED backlight: STO550AP5_51LED R / L REV01_161027
T-CON: 17Y_HU11APHTA44LV0.0
LED driver (backlight): integrated into MainBoard
Power Supply (PSU): ACDP-209A1 2955036304
MainBoard: 1-981-926-21
IC MainBoard: CPU: MT5597BMEJ, EMMC: THGBMOG5D1LBAIL
Tuner: CE251ZP
Technical Specifications KD-55XE7077
SONY KD-55XE7077
General repair guidelines for TV LCD LED
Possible malfunctions
- The SONY KD-55XE7077 TV does not turn on, does not respond to the remote control and the control panel buttons, the indicators do not light or flash.
In some of these cases, a malfunction is detected in the APDP-209A1 Power Module. It is necessary to measure the output voltages in its secondary circuits, and if they are completely absent, it is necessary to check the serviceability of power switches and rectifier diodes for possible breakdown (short circuit).
In case of any breakdown of semiconductors in the secondary circuits, the converter can usually work normally in emergency short circuit mode. There are no output voltages. And with a short circuit in the power elements of the primary circuit, as a rule, the mains fuse breaks and less often the current sensor at the source of the key.
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, the screen is black, there is sound, with external illumination of the screen, you can sometimes see barely noticeable outlines of the image.
As a rule, in this case, the LED backlight turns out to be faulty. The reason can be found in the malfunction of the LEDs, in the violation of the contact connections of the LED strips, or in the provision of their power (LED-driver).
To check the LED strips, to open all the transitions of the LEDs, several tens of volts or more are needed, it is best to use a current source for such purposes. The breakage of several PN junctions connected in series cannot be detected with a multimeter or tester. In such cases, it is necessary to open the panel and check each LED. If your multimeter cannot open the LED transitions in forward bias, sometimes you can detect the presence of a PN junction of the protective zener diode by connecting the probes in the opposite direction. If the zener diode is broken or broken in short-circuit, then the LED is faulty and needs to be replaced.
- 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). Sometimes it is necessary to check or replace (if necessary) the elements of the MainBoard - CPU: MT5597BMEJ, EMMC: THGBMOG5D1LBAIL. In cases where the BGA processor is used, its malfunction is usually detected by the local heating method.
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 CE251ZP tuner and update the software. The pulses from the I2C bus must be controlled with an oscilloscope.
We recommend the owners of the KD-55XE7077 TV for repair only to qualified specialists with the necessary work experience! Self-repair attempts without the appropriate knowledge and skills can lead to irreversible negative consequences!



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-55XE7077:
Installed matrix (LED-panel) V550QWSE06.
The matrix control uses the Timing Controller (T-CON) 17Y_HU11APHTA44LV0.0.
To power the backlight LEDs, a converter is used, combined with the main board 1-981-926-21.
The formation of the necessary supply voltages for all nodes of the SONY KD-55XE7077 TV is carried out by the ACDP-209A1 power module, or its analogues.
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.


Brand: SONY, Model: KD-55XE7077.
Briefly from the TV: LCD, LED backlight, 54.6 ", 3840x2160, 4K UHD, HDR, DVR, there is a satellite tuner, sound: 20W, HDMI: 3, Internet access, Wi-Fi, Smart TV.
Producer: Malaysia / Slovakia (Nitra) Developer: Sony Corporation. Japan
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 and LCD-panel V550QWSE06.
Power Supply Unit (PSU) ACDP-209A1 2955036304 Power Supply.
SONY KD-55XE7077 TV with V550QWSE06 LCD display, diagonal size 54.6 "(139 cm) 16: 9 format. The required brightness of the screen is 350 cd / m² LED backlight LED. The ratio of maximum brightness to minimum (contrast) is 3300: 1 .This model uses side lighting from Edge LEDs.
The V550QWSE06 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-55XE7077 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 147 watts.
Overall dimensions: with stand 1238x775x252 mm, without stand 1238x722x58 mm.
TV Weight: with stand: 18.6 kg, without stand: 17.7 kg.
Attention! The V550QWSE06 panel of the SONY KD-55XE7077 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.