Wednesday 11 March 2020

REPAIR / SERVICING TV SONY KLV-52V550A

Technical description and composition of the TV SONY KLV-52V550A, type of panel and applicable modules. The composition of the modules.
SONY
Model: KLV-52V550A
Chassis / Version: EX2L RU
Panel: LTY520HB11
T-CON: NP_HAC2LV1.1
Inverter (backlight): LJ97-02039A
Power Supply (PSU): APS-245 1-879-246-11 148734011
MainBoard: 1-878-942-12 BA board A1729824A
IC MainBoard: CPU: MC10147F1 410, MB91F313A, NAND Flash: K9F1208UOC, EEPROM: 24C32
Tuner: BTD-HF422T
Control: RM-GA015
Technical Specifications KLV-52V550A
SONY KLV-52V550A
General recommendations for repairing TV LCD
Possible manifestations of defects
- SONY KLV-52V550A 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.
In such cases, the APS-245 power supply is usually faulty. In the general case, in the absence of the necessary supply voltages in the secondary circuits of all converters, it is necessary first of all to check the power switches and rectifier diodes for a possible partial or complete breakdown. First of all, check all the elements of the standby mode.
In case of breakdowns of the diodes in the secondary circuits, the converters can operate in emergency short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse usually breaks, sometimes low-resistance resistors are current sensors at the source of the keys, which are also subject to verification.
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 a PWM chip, damping and frequency-setting circuits, or elements of OOS (negative feedback) stabilization. The reason for the breakdown of the power keys can be the PWM controllers themselves (PWM), which are usually checked by replacement.
- 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.
These manifestations can be triggered by a power module, or by defects in the inverter, as well as a distortion of the currents in the lamps due to their uneven wear. If all the electrolytic capacitors of the filter according to the inverter power supply are serviceable, you should make sure that the lamps are in good working condition, then you need to check the converter keys and the secondary windings of the transformers.
Sometimes, for diagnostic purposes, inverter protection must be disabled. In such cases, special care must be taken during work, and the protection circuits should be restored immediately after the repair is completed.
- 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 1-878-942-12 should begin by checking the stabilizers and power converters needed to power the microcircuit and matrix. If necessary, update or replace the software (software). Board repair and replacement of CPU chips: MC10147F1 410, MB91F313A, NAND Flash: K9F1208UOC, EEPROM: 24C32 are carried out with the necessary equipment, and the corresponding element base. Faults associated with the application of BGA processor soldering technologies can be localized by the heating method.
If there is no reception of television channels, but the TV is working properly from external devices, first of all it is necessary to check the voltage of the BTD-HF422T tuner and update the software. The pulses from the I2C bus must be controlled with an oscilloscope.
We recommend the owners of the KLV-52V550A 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!

Service / Schematic  manual ----------------->   Sony KLV-32V530A, 32V550A/R/W, 40V530A 40V550A/R/W, 46V550A, 52V550A, CHASSIS EX2L    KLV-32V530A, KLV-32V550A, KLV-32V550A/R, KLV-32V550A/W, KLV-40V530A, KLV-40V550A, KLV-40V550A/R, KLV-40V550A/W, KLV-46V550A, KLV-52V550A


 The appearance of MainBoard 1-878-942-12 is shown in the figure below:
1-878-942-12
1-878-942-12 can be used on TVs:
SONY KDL-46V5500 (Panel LTY460HB11), SONY KLV-32V550A (Panel LTY320HA03 A06), SONY KLV-40V550A (Panel LTY400HA12), SONY KLV-52V550A (Panel LTY520HB11), SONY KDL-46V5610 (Panel LTY460HB10), SONY KDL-32V5610 (Panel LTY320HA02), SONY KDL-32V5500 (Panel LTY320HA02).
The appearance of the power supply
Main features of the device SONY KLV-52V550A:
Installed matrix (LCD panel) LTY520HB11.
The matrix control uses the Timing Controller (T-CON) NP_HAC2LV1.1.
To power the backlight used inverter LJ97-02039A.
The formation of the necessary supply voltages for all nodes of the SONY KLV-52V550A TV is carried out by the APS-245 power module, or its analogs.
MainBoard - the main board (motherboard) is a module 1-878-942-12, using CPU chips: MC10147F1 410, MB91F313A, NAND Flash: K9F1208UOC, EEPROM: 24C32 and others.
The BTD-HF422T tuner provides TV reception and channel tuning.