Tuesday 10 March 2020

REPAIR / SERVICING TV SONY KDL-55WD655

Technical description and composition of the SONY KDL-55WD655 TV, panel type and applicable modules. The composition of the modules.
SONY LED
Model: KDL-55WD655
Chassis / Version: 715G7852
Panel: TPT550F2-FHBN20.K REV: S48P0D
LED backlight: GJ-2K16-550-D712-S1-R / L
T-CON: 47-6021023 HV550WU2-370
LED driver (backlight): integrated into PSU
Power Supply (PSU): 715G7793-P01-001-0H2S
MainBoard: 715G7852-M0A-000-005K
Tuner: CE243ZP
Control: IR: 715G8057-R01-000-004K, WiFi: WN4639R V01 323K178021YD
Technical Specifications KDL-55WD655
SONY KDL-55WD655
General repair guidelines for TV LCD LED
Possible malfunctions
- The SONY KDL-55WD655 TV does not turn on at all. The control lights do not light or flash. The TV on the remote control and the control panel buttons do not respond.
With similar manifestations, in some cases, the 715G7793-P01-001-0H2S power module is faulty. It is necessary to measure its output voltages, and in case of their absence (full or partial), it is necessary to check the serviceability of the power switches of the converters and rectifier diodes for the presence of a possible 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 during 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 an excess of the maximum current or voltage. 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.
A malfunction is usually most likely in these cases at the backlight nodes of the display matrix. The reason can be both in the power supply of the LEDs, in their serviceability (breakdown or breakage), as well as in the violation of the contact connections of the LED strips.
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 TV does not enter the operating mode, does not respond to the remote control. The indicator on the front panel lights constantly or blinks.
Repair or diagnostics of the 715G7852-M0A-000-005K motherboard should be started by checking the stabilizers and power converters needed to power the microcircuits and matrix. If necessary, update or replace the software (software).
If you suspect a malfunction of the CE243ZP tuner, first of all, you need to verify the correctness of the software, as well as the presence of the necessary voltage levels and pulses of data exchange with the processor via the I2C bus at the corresponding terminals of the tuner.
TV users and owners need to remember that attempts to self-repair a SONY KDL-55WD655 TV without the appropriate qualifications and necessary experience can lead to serious negative consequences!





The appearance of the MainBoard 715G7852-M0A-000-005K is shown in the figure below:
715G7852-M0A-000-005K
The appearance of the power supply
Main features of the device SONY KDL-55WD655:
Installed matrix (LED panel) TPT550F2-FHBN20.K REV: S48P0D.
The matrix control uses the Timing Controller (T-CON) 47-6021023.
To power the backlight LEDs, a converter is used, combined with a power supply.
The formation of the necessary supply voltages for all nodes of the SONY KDL-55WD655 TV is carried out by the power supply module 715G7793-P01-001-0H2S, or its analogues.
MainBoard - the main board (motherboard) is a 715G7852-M0A-000-005K module.
The CE243ZP tuner provides television reception and channel tuning.


SONY KDL-55WD655 TV with TPT550F2-FHBN20.K LCD display, 55 "(140 cm) diagonal size in 16: 9 format. LCD backlight uses Direct LED backlighting.
The TPT550F2-FHBN20.K panel and the motherboard software 715G7852-M0A-000-005K provide for viewing HD and Full HD images at a resolution of 1920x1080 pixels in a graphical decomposition according to the standard 1080p (Full HD).
The KDL-55WD655 is equipped with SMART software, built-in applications and the ability to work on the Internet. Connecting to the Internet can be done via Wi-Fi. Video processor supported multimedia file formats: MP3, MPEG4, DivX, 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), component, SCART, HDMI x4, USB x3, Ethernet (RJ-45), Wi-Fi, WiDi. An output for connecting headphones is provided.
The digital tuner is capable of receiving television channels in the standards DVB-T, DVB-C, DVB-T2, DVB-S2.
Overall dimensions: with stand 1239x775x278 mm, without stand 1239x722x94 mm.
TV Weight: with stand: 18.1 kg, without stand: 16.8 kg.
Attention! Panel TPT550F2-FHBN20.K REV: S48P0D LED-TV SONY KDL-55WD655 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.