Technical description and composition of the TV SONY KDL-55W905A, type of panel and applicable modules. The composition of the modules.SONY LED
Model: KDL-55W905A
Panel: YLV5522-02N
T-CON: 1-888-061-11 (173410711) - A1919762A
LED driver (backlight): ST4055LD-S03 - REV: 1.0
Power Supply (PSU): 1-888-119-11 APS-344
PWM Power: MIP2H2 (Standby)
MainBoard: 1-888-101-32 - 173415632 - Y200A420B BA2S
IC MainBoard: A8298 1248 271L (5x5), 54429 A382 (14), 1011047 D3R2 (16). 1110021 AZ7V (14), SiI9589CTUC
Tuner: Y200A420A
Control: RM-ED052, RMF-ED003
Appearance
SONY KDL-55W905A
General repair guidelines for TV LCD LED
SONY KDL-55W905A, like other televisions, it is advisable to start repairing with a careful examination of the external and internal elements and modules. Many visible changes in the state of the elements make it possible to determine the further direction of troubleshooting and localization of the defect. Elements with visible damage, for example, capacitors swelled up after boiling the electrolyte, charred resistors in certain nodes of the circuit, as well as ring cracks in solders will help the master to guess the causes and possible consequences of the malfunction.
If the TV does not turn on, no indicators on its front panel are lit or blinking. Also, if the TV does not respond to the remote control and buttons, does not make any sounds or any signs of operability when turned on, there is a certain probability that the power module is defective and needs repair. Sometimes with similar manifestations a problem can only occur in the absence of processor power, which is typical for certain SONY models. When diagnosing and repairing the power supply, after replacing the swollen capacitors of the secondary rectifier filters (if any), you must first check the mains fuse. When it is broken, the power elements of transistors and rectifier bridge diodes should be checked for avalanche (thermal) breakdown.
It should be remembered that in the practice of repair, usually the power switches in switching power supplies (SMPS) do not fail due to their poor quality and, in such cases, it is necessary to look for the cause that led to a malfunction and provoked a breakdown of the key. Most often, the culprits of the accident are dried electrolytic capacitors or dangling resistors in the primary circuit, or the PWM controller chip itself may be faulty. It is also necessary to check all the semiconductor elements of the stabilization circuit in the primary and secondary circuits.
In cases where the SONY KDL-55W905A TV has lost an image, and the sound is there and all other functions are operational, there is a possibility of a malfunction of the LED driver (converter for powering the panel backlight LEDs). When you turn on the TV, the image may appear briefly and disappear immediately. It must be borne in mind that with such manifestations the LEDs themselves also fail.
In most cases of lack of backlight, it becomes necessary to disassemble the panel in order to check the LEDs, connectors, loops and all contact connections. If one or several LEDs does not work in one line, therefore, they are broken and should be replaced.
An open in the LED lines connected in series cannot be detected using a multimeter or tester without disassembling the panel. To open all the transitions, several tens of volts are needed, and it is best to use a current source for such purposes.
Repair of the BA2S motherboard should begin with the diagnosis and verification of all linear stabilizers or power converters of its microcircuits. Sometimes it may be necessary to update the software (software) - flashing FLASH or EEPROM.
If it is not possible to replace the MB (SSB) board, you need to check the health of its elements - A8298 1248 271L (5x5), 54429 A382 (14), 1011047 D3R2 (16). 1110021 AZ7V (14), SiI9589CTUC. Defective components should be replaced.
Before replacing the Y200A420A tuner, if there is no tuning to the channels, you must first check the supply voltage at its terminals, including the varicap supply (30-33V).
Owners and users of the SONY KDL-55W905A TV must 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 1-888-101-32 is shown in the figure below:1-888-101-32
The appearance of the power supply
Main features of the device SONY KDL-55W905A:
Installed matrix (LED panel) YLV5522-02N.
The matrix control uses the Timing Controller (T-CON) 1-888-061-11.
The LED driver ST4055LD-S03 is used to power the backlight LEDs.
The formation of the necessary supply voltages for all nodes of the SONY KDL-55W905A TV is carried out by the power module 1-888-119-11, or its analogs using MIP2H2 (Standby) microcircuits.
MainBoard - the main board (motherboard) is a module 1-888-101-32, using microchips A8298 1248 271L (5x5), 54429 A382 (14), 1011047 D3R2 (16). 1110021 AZ7V (14), SiI9589CTUC and others.
The Y200A420A tuner provides television reception and channel tuning.