Technical description and composition of the SONY KDL-40R474A TV, panel type and applicable modules. The composition of the modules.SONY LED
Model: KDL-40R474A
Chassis / Version: RB1FK
Panel: S400DH1-2 // S400DH1-3
LED backlight: SVG400A81_REV 3_121114
LED driver (backlight): integrated into PSU
PWM LED driver: BD9488F
MOSFET LED driver: KF3N40W, KF5N50FZA
Power Supply (PSU): APS-349 (CH) 1-888-121-11
PWM Power: BD7677FJ-GE2, CXA3810M (PFC & PWM resonant), MIP2H2 (StandBy)
MOSFET Power: KF11N50F, KF5N50FZA
MainBoard: 1-895-375-51 - Y200A520A - 1P-012CJ01-4010
IC MainBoard: MT5367ZUHU
Tuner: SUTRE227TN
Control: IR: 1P-112B801-2010
Technical Specifications KDL-40R474A
SONY KDL-40R474A
General repair guidelines for TV LCD LED
The SONY KDL-40R474A TV, like many other electronic devices, it is advisable to start repairing by inspecting all external and internal elements. It often happens that visible damage to elements or connections helps determine the direction of the troubleshooting. Carbonized paint on the upper layer of resistors, electrolytic capacitors of rectifier filters swollen after boiling, cracked soldering at the terminals of heating elements or transformers can often suggest the cause of the defect and possible consequences.
If the KDL-40R474A TV does not turn on, does not make any sounds when it is turned on, and also no indicators on the front panel light or blink - there is a high probability of a malfunction in the power module. In some cases, only the stabilizer or power converter of the control processor may be faulty, which is typical for some SONY models. Diagnostics and repair of the common power supply should always begin with a check of the mains fuse and the condition of the electrolytic capacitors of the secondary rectifier filters. Defective and swollen capacitors should be replaced with new ones. If the fuse breaks, it is advisable to check for a breakdown, first of all, all the power semiconductor elements of the converter and the diode bridge of the rectifier network, as well as the large electrolytic capacitor of the filter of the rectifier network.
It should be borne in mind that in the practice of repair it is extremely rare that key transistors in switching power supplies (SMPS) fail for no reason that should be sought by checking other components, for example, a breakdown of the key can provoke faulty elements of the damper circuits, or dried electrolytic capacitors or dangling primary resistors BP circuits involved in the stabilization process. In this case, all semiconductor elements of the strapping of the PWM controller chip are subject to verification, which it is desirable to verify by replacement.
If the SONY KDL-40R474A does not have an image, but there is sound and the TV is controlled by the remote control, a malfunction in the backlight circuits of the S400DH1-2 panel is likely. The LEDs or the power converter - LED driver may be faulty. Often in such cases, when you turn on the TV, an image appears and immediately disappears. First of all, it is necessary to verify the operability of the electrolytic capacitors of the rectifier filter supplying the LED driver, and check the LEDs, connecting obviously known good diagnostics.
Often there is a need for disassembling the panel to check the health of the LEDs, as well as contact connections in the connectors and soldering.
When trying to detect a break in the LED lines, it should be taken into account that it is difficult to do this without disassembling the panel. For example, a current source is needed to open PN junctions connected in series.
If the ML1 motherboard is faulty, first of all it is necessary to check all the linear stabilizers or power converters of its chips, and also, if necessary, update the software. Sometimes you can check the health of MB only by replacement.
In cases of attempts to repair the MB board (SSB), it is necessary to check the serviceability of its elements - MT5367ZUHU which may require replacement with new ones. If a BGA processor is installed, there is a possibility of a violation of the soldering of the contacts of its conclusions with the board (it is diagnosed by heating).
Before replacing the SUTRE227TN tuner, if there is no tuning to the channels, you must first check the supply voltage at its terminals, including the power supply of varicaps (30-33V).
Owners and users of the SONY KDL-40R474A 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!
Schematic Diagram / Service manual --------------> Sony KDL-32R420A/421A/423A/424A, KDL-40R470A/471A/473A/474A/470A/473A Chassis RB1FK
PSU / Service manual --------------> Sony ASP-348, ASP-349, ASP-350
The appearance of MainBoard 1-895-375-51 is shown in the figure below:1-895-375-51
1-895-375-51 can be used in TVs:
SONY KDL-40R473A (Panel S400DH1-3), SONY KDL-40R474A (Panel S400DH1-2), SONY KDL-46R473A (Panel S460DH1-1).
PSU Advanced
The KDL-40R474A model uses an ASP-349 power supply unit using the PFC (Power Factor Correction) node - an active filter of the highest harmonics of the current consumption. In fact, it is a boost converter based on the CXA3810M & PWM resonant PWM controller, which eliminates the charge current of the rectifier filter's electrolytic capacitor directly from the network through open diodes when its charging current is determined by its reactance.
As a result of the operation of the converter, the envelope of high-frequency pulses of the input current of the converter will repeat the shape and phase of the input voltage. The health of the PFC node can be indirectly judged by the presence of an increased constant voltage (about + 380V) on the capacitor of the rectifier network in operating mode.
The appearance of the power supply
Main features of the device SONY KDL-40R474A:
Installed matrix (LED-panel) S400DH1-2 or S400DH1-3.
To power the backlight LEDs, a converter is used, combined with a power supply, controlled by a BD9488F PWM controller. As the power elements of the LED driver, keys of the type KF3N40W, KF5N50FZA are used.
The necessary supply voltages for all nodes of the SONY KDL-40R474A TV are generated by the APS-349 power module or its analogs using BD7677FJ-GE2, CXA3810M (PFC & PWM resonant), MIP2H2 (StandBy) microchips and power switches of the KF11N50F, KF5N50FZA type.
MainBoard - the main board (motherboard) is a 1-895-375-51 module, using MT5367ZUHU chips and others.
The SUTRE227TN tuner allows you to receive television programs and tune to channels.