Saturday, 21 August 2021

REPAIRING / SERVICING TV SONY KD-55XH9077

Technical description and composition of the TV SONY KD-55XH9077, type of panel and modules used. Module composition.
Composition  /  Specifications
SONY KD-55XH9077
LCD TV LED Smart UHD KD-55XH9077 | Year of manufacture: 2020
Screen diagonal: 54.6" (139cm)
Screen format: 16:9
Resolution: 3840x2160
LED backlight: LED Direct LED
Smart: Yes
Operating system: Android
HD support: 4K UHD, HDR
Viewing Angle: 178°
Progressive scan: Yes
Digital tuner: DVB-T, DVB-T2, DVB-C, DVB-S
Teletext: Yes
Multimedia: MP3, WMA, MPEG4, HEVC (H.265), Xvid, MKV, JPEG
Sound stereo: there is
Sound power: 20W
Interface: AV, HDMI x4, USB x2, Ethernet (RJ-45), Bluetooth, Wi-Fi 802.11ac
Headphone jack: yes
TV weight: with stand 17.5 kg
Without stand: 16.5 kg
Dimensions: with stand 1231x780x338mm
without stand 1231x710x70mm
Mains power consumption: 195W

SONY KD-55XH9077

SONY LED
Model: KD-55XH9077

Panel: YDAS055DND01

LED backlight: MBL-55030D612SN0-SN1

T-CON: 20Y_S65JU22MQV0.1 LMY550FF06-A

LED driver (backlight): 1-006-904-11 (100690311)

PWM LED driver: OZ9218AETN

Power Supply (PSU): AC21202 B55D-32E

PWM Power: PFC, PWM

MOSFET Power: N-FET TO-220F

MainBoard: 1-006-895-31 A5014782A

IC MainBoard: CPU, eMMC, DRAM, AUDIO, DC/DC

MainBoard: PE641ZP

Control: IR 1-003-969-12, WiFi: DHUR-SY63
General advice about LCD LED TV repair
Possible problems

- SONY KD-55XH9077 TV does not turn on and does not show any signs of turning on, the control buttons and the remote does not respond.

In such cases, the problem should be sought in the first place in the power module AC21202. Then we recommend to measure its output voltages, and if not, check the functionality of the power switches (N-FET TO-220F) and inverter rectifier diodes for possible short circuits.
If there is a breakdown in the secondary circuits of the inverter, the inverter can usually be short-circuited, and if there is a short in the primary circuit power elements, the mains fuse or the current sensor at the source of the switch will most often blow.
Mos-Fet switches used in switching power supplies usually fail due to the failure of other elements, which can take it out of key mode, or cause it to exceed the maximum current or voltage. These may be the circuits feeding the PWM controller, the damping or frequency-retaining circuits, or the negative feedback elements in the stabilization circuit. PWM controllers (PFC) PFC, PWM, if there is no external damage and short circuit between pins, are checked by replacing with known good ones.

- No picture, sound is present, all other TV functions work. When switching on, the picture may sometimes appear for a second.

Failure in these cases is usually most likely in the backlighting nodes of the display matrix. Often the cause is a faulty LED (breakage, short circuit, etc.), or connectors of the bars (strings) MBL-55030D612SN0-SN1, less often the LED-driver is faulty.
To check the LED strips for breakage without disassembling the panel can help, for example, a current source. It is not possible to open the series-connected PN-junctions with a simple multimeter, you will need a voltage of about several tens of volts.

READ HOW TO REPAIR THE TV LED BACKLIGHT --------------> HERE.


- The TV set doesn't turn on, the LED indicates standby or working mode, or blinks.

Repair or diagnosis of the motherboard 1-006-895-31 should begin with checking the stabilizers and power converters needed to power the chips and matrix. If necessary, software (software) should be updated or replaced.

Warning. Users and owners of TV sets KD-55XH9077, not having the appropriate qualifications, knowledge and experience, strongly recommend not attempting self-repair to avoid the negative consequences which could lead to total unrepairability of the device.

More on MainBoard repair

An exterior view of the MainBoard 1-006-895-31 is shown in the illustration below:

1-006-895-31

MainBoard Appearance



The main features of the device SONY KD-55XH9077:

A matrix (LED panel) YDAS055DND01 is installed.
Timing Controller (T-CON) 20Y_S65JU22MQV0.1 is used to control the matrix.
The LED driver 1-006-904-11 is used to power the backlight LEDs and is controlled by the OZ9218AETN PWM controller.
Forming the necessary supply voltages for all TV SONY KD-55XH9077 components is implemented by a power module AC21202, or its analogues using PFC, PWM and power switches N-FET TO-220F.
MainBoard - the main board (motherboard) is a module 1-006-895-31, with the use of chips CPU, eMMC, DRAM, AUDIO, DC/DC and others.
The PE641ZP tuner provides television program reception and channel tuning.

SONY KD-55XH9077 TV with a 54.6" (139 cm) 16:9 LCD screen diagonally. The LCD panel uses a backlighting of Direct LEDs.
The design and technical capabilities of the TV can realize an image in the highest quality UHD at a resolution of 3840x2160 pixels in the standard 4K UHD, HDR. Image processing is made by modern technology High Dynamic Range (HDR) with an extended range of brightness gradation.
The KD-55XH9077 has built-in SMART software and pre-installed Android OS. Video Processor supported file formats of multimedia: MP3, WMA, MPEG4, HEVC (H.265), Xvid, MKV, JPEG.
The power of the sound system is 20 W. NICAM stereo processing system and Sound Surround surround sound function is used.
External interface (connection to other devices) is supported by standard inputs and outputs: antenna input (RF), AV, HDMI x4, USB x2, Ethernet (RJ-45), Bluetooth, Wi-Fi 802.11ac. There is a headphone output. The digital tuner is capable of receiving DVB-T, DVB-T2, DVB-C, DVB-S, DVB-S2 TV channels.

Power consumption in mains mode is 195 W.

Overall dimensions: with stand 1231x780x338 mm, without stand 1231x710x70 mm.

TV weight: with stand 17.5 kg, without stand 16.5 kg.

Warning. The SONY KD-55XH9077 LED TV panel is the most expensive part of the TV.
Avoid hitting the glass and excessive pressure on the surface of the screen to avoid damage to the LED panel!
It is not safe to get any liquid on the screen. Sometimes a single drop of water is enough, if it drips down the glass onto the stubs, the TV may become unrepairable.