Technical description and composition of the SONY KDL-55NX720 TV, panel type and applicable modules. The composition of the modules.SONY LED
Model: KDL-55NX720
Chassis / Version: AZ2-F
Panel: LSY550HJ02
T-CON: LJ94-03929H (EDL_4LV0.3)
LED driver (backlight): SSL4055_2E4A REV: 1.0 10.08.24
Power Supply (PSU): APS-299 1-884-525-12, DPS-76 (CH) 1-884-407-11
PWM Power: CXA3811M, CXA3799AM, MIP2H2
MainBoard: BAT_L 1-883-754-12
IC MainBoard: CPU: CXD4727GB, RTL8201ES, TDK 6T213LF, Si19287BCNU, GL850G MN1GD07G21, PS54425, D9583D (32), RP1E070 (6)
Technical Specifications KDL-55NX720
SONY KDL-55NX720
General repair guidelines for TV LCD LED
The SONY KDL-55NX720 TV, like many other electronic devices, it is advisable to start repairing by inspecting all external and internal elements. Often, based on certain external signs, it may be possible to draw certain conclusions about the reasons for the failure of certain elements of the circuit even before the necessary measurements are made, which will determine the further algorithm for troubleshooting and localizing the defect. If charred resistors, swollen electrolytic or cermet capacitors, ring cracks in the solders of the terminals of transformers or heating elements are found, it is advisable to establish the causes and consequences of the malfunction that has arisen, as well as to check the connected elements and assemblies.
In cases where the SONY KDL-55NX720 TV does not turn on, does not respond to the remote control and buttons, no indicators on the front panel light up or blink, and there are no sounds and no signs of operability when turning on, the APS-299 power supply module is most likely faulty 1-884-525-12, DPS-76 (CH) 1-884-407-11 or there is no standby power supply. First of all, it is necessary to replace the swollen capacitors of the rectifier filters, if any. If the mains fuse is cut off in the power supply, in most cases a breakdown of the power key (s) is detected, which can be integrated with the PWM controller, or a separate field-effect transistor can be used. The rectifier bridge diodes and the electrolytic capacitor of the mains rectifier filter should also be checked.
As a rule, the keys in switching power supplies (SMPS) are reliable enough and rarely fail for no reason to be looked for by checking other components of the circuit - electrolytic capacitors, resistors and semiconductor elements of the primary circuit. The PWM chip is verified by replacing it with a known good one.
If, when you turn on the TV, the image appears and immediately disappears, or is missing initially when you turn on, but the sound has other functions that work, there is a greater likelihood of a malfunction of the LED driver (power converter for the backlight LEDs of the LSY550HJ02 panel).
The lack of backlight often occurs due to an open circuit in the LED circuit. There is a need for disassembling the panel and checking the LEDs themselves, as well as the same contact connections in the connectors and rations of the terminals.
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.
Diagnosis and repair of the BAT L 1-883-754-12 motherboard usually begins with a test of the performance of the stabilizers and power converters of the module chips. In some cases, a software update is required.
Attention! For users and owners of KDL-55NX720 TVs who do not have the appropriate qualifications, knowledge and experience, we strongly recommend against attempting self-repair in order to avoid negative consequences that could lead to complete non-serviceability of the device.
Service manual / schematic diagram -------------------> Sony KDL-40/46/55NX720 CHASSIS AZ2-F
1. Service Manual with Schematic Diagram 62 pages of 2011 for the -------------------> KDL-40NX720, KDL-46NX720, KDL-46NX720, KDL-55NX720, KDL-55NX720, KDL-60NX720
2. Service Manual 146 pages of 2011 for the models -------------------> KDL-40NX720, KDL-40NX723, KDL-40NX725, KDL-46NX720, KDL-46NX723, KDL-46NX725, KDL-55NX720, KDL-55NX723, KDL-55DX-57NX720 , KDL-60NX723, KDL-60NX725.
The appearance of MainBoard BAT_L is shown in the figure below:BAT_L
BAT_L can be used on TVs:
SONY KDL-40NX720 (Panel LSY400HF01), SONY KDL-55NX720 (Panel LSY550HJ02), SONY KDL-46HX920 (Panel FQLF460DT01).
The appearance of the power supply
Main features of the device SONY KDL-55NX720:
Installed matrix (LED-panel) LSY550HJ02.
The matrix control uses the Timing Controller (T-CON) LJ94-03929H.
The LED driver SSL4055_2E4A is used to power the backlight LEDs.
The necessary supply voltages for all nodes of the SONY KDL-55NX720 TV are generated by the APS-299 power module or its analogs using CXA3811M, CXA3799AM, MIP2H2 microcircuits.
MainBoard - the main board (motherboard) is a BAT_L module using CPU chips: CXD4727GB, RTL8201ES, TDK 6T213LF, Si19287BCNU, GL850G MN1GD07G21, PS54425, D9583D (32), RP1E070 (6) and others.