Technical description and composition of the SONY KDL-43WD755 TV, panel type and applicable modules. The composition of the modules.SONY LED
Model: KDL-43WD755
Panel: T430HVF03.0
LED backlight: 7443T08.002-2-DX1 LB43012 V0_00, V1_00
T-CON: T430HVN01.9 43T01-C0A
LED driver (backlight): integrated into MainBoard
Power Supply (PSU): Adapter 19V
MainBoard: 1-980-335-23 (173587123) A2103243B
IC MainBoard: CPU: MT5566CQVT
Tuner: CE251ZP
Control: IR: 1-980-526-11 (173597611), WiFi: 1-458-900-11 J20H090
Technical Specifications KDL-43WD755
SONY KDL-43WD755
General repair guidelines for TV LCD LED
Possible malfunctions
- SONY KDL-43WD755 does not turn on, the indicators on the front panel do not light up and do not blink. The TV does not respond to the control buttons and the remote control.
Most often, with such manifestations, the main adapter power module is found to be faulty.
The owner of the TV can purchase an external power supply unit such as Adapter and repairing it is not always advisable. In any case, the simplest typical defects characteristic of most IIP schemes can be easily detected and eliminated after opening. In the absence of the necessary supply voltages in the secondary circuits of the converters, it is necessary to check the power switches and rectifier diodes for a possible partial or complete breakdown.
In case of breakdowns in the secondary circuits, the converter can operate in a short circuit mode, and during a short circuit in the elements of the primary circuit, the mains fuse 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 frank short-circuit between the terminals, are checked by replacing with new, or obviously working.
- There is no image, there is sound, it responds to the remote control, the channels are switched. In some cases, the image appears when you turn on and immediately disappears.
In most of these cases, a malfunction is detected in the nodes and backlight elements of the LED panel. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
It is impossible to check the LED line for breaks without disassembling the panel with a multimeter or tester. For these purposes, it is necessary to open all series-connected PN junctions and a voltage of the order of tens of volts will be required, and ideally, a current source. Having disassembled the panel, it is necessary to check each LED separately. Chinese multimeters, as a rule, light up a single 3-volt LED in the forward direction. In the case of using dual 6-volt LEDs, the PN junction of its protective zener diode can serve as a health indicator. In faulty LEDs, the zener diode will either be cut off or broken into short-circuit.
- 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 motherboard 1-980-335-23 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: MT5566CQVT. 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.
Attention! For users and owners of KDL-43WD755 TVs who do not have the appropriate qualifications, knowledge and experience, we categorically do not recommend attempting self-repair in order to avoid negative consequences that could lead to complete non-repairability of the device.
The appearance of MainBoard 1-980-335-23 is shown in the figure below:1-980-335-23
Main features of the device SONY KDL-43WD755:
The matrix (LED panel) T430HVF03.0 is installed.
The matrix control uses the Timing Controller (T-CON) T430HVN01.9.
To power the backlight LEDs, a converter is used, combined with the main board 1-980-335-23.
To power all internal components of the SONY KDL-43WD755 TV, an external adapter 19V type source is used.
MainBoard - the main board (motherboard) is a module 1-980-335-23, using CPU chips: MT5566CQVT and others.
The CE251ZP tuner provides TV reception and channel tuning.
