Saturday 7 March 2020

REPAIR / SERVICING TV SONY KDL-40CX521

Technical description and composition of the SONY KDL-40CX521 TV, panel type and applicable modules. The composition of the modules.
SONY
Model: KDL-40CX521
Chassis / Version: AZ2F
Panel: LTY400HM07
T-CON: ESP_OB_S4LV0.4
Inverter (backlight): SSI400_10B01 REV 1.0
Power Supply (PSU): APS-282 1-883-861-11 // G2BS-C 3H371W PSC10355 M 147428211
PWM Power: L6562, CXD9841P, MIP2H2
MOSFET Power: K15A50D
MainBoard: 1-883-753-32
IC MainBoard: CXD4727GB, K4B2G1646C-HCH9, Gl850g (MN1GD07G21), KFM2GN6Q2B, SII9287BCNU PS54452, D95830, RTL8201ES
Tuner: CXD2825GA
Technical Specifications KDL-40CX521
SONY KDL-40CX521
General recommendations for repairing TV LCD

Possible malfunctions
- The SONY KDL-40CX521 TV does not turn on. There are no signs of operability. The indicators on the front panel do not light or flash, the TV does not respond to the remote control and control buttons.
With such manifestations, the APS-282 power module usually fails. It is necessary to measure its output supply voltage, and in case of their absence, check the serviceability of the power switches (K15A50D) of the converters and rectifier diodes for the probability of breakdown in PN semiconductor junctions.
In case of breakdowns of diodes in the secondary circuits, the converter can operate in emergency short circuit mode without output voltages, and during short circuit in the power elements of the primary circuit, the mains fuse and / or current sensor at the source of the key 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 L6562, CXD9841P, MIP2H2, in the absence of visible damage or open faults between the terminals, are checked by replacing with new ones, or obviously working.
- There is no image, but there is sound, it responds to the remote. Or the image appears when you turn it on and immediately disappears
The defect can be caused by problems in the nodes or elements of the backlight of the display, or in the power supply of the lamps or the inverter.After checking all the electrolytic capacitors of the filters that are involved in the power supply to the inverter, you must ring in its converter power keys for breakdown and secondary windings of transformers for an open.



If in diagnosing a malfunction, it is necessary to disable the inverter protection, there is a risk of failure of the power elements of the inverter, and special care is required when working, and after they are finished, it is necessary to restore the protection circuits for further safe operation of the TV by the owner in normal mode.
- The TV does not turn on, does not respond to the remote control. The indicator blinks or signals standby mode.
Repair or diagnostics of the 1-883-753-32 motherboard 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 the CXD4727GB, K4B2G1646C-HCH9, Gl850g (MN1GD07G21), KFM2GN6Q2B, SII9287BCNU PS54452, D95830, RTL8201ES microcircuits 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 you need to check the voltage of the CXD2825GA tuner and update the software. The pulses from the I2C bus must be controlled with an oscilloscope.
Once again, we remind TV users: you should not make attempts to repair it yourself without the appropriate knowledge, experience and the necessary qualifications! Entrust repair to professionals with sufficient experience in the field of repair of electronic equipment.


The appearance of MainBoard 1-883-753-32 is shown in the figure below:
1-883-753-32
1-883-753-32 can be used in TVs:
SONY KDL-32CX520 (Panel V315H3-L01), SONY KDL-32EX421 (Panel LTY320AN02), SONY KDL-32EX720 (Panel LTY320HJ01), SONY KDL-40EX521 (Panel LTY400HM08 001), SONY KDL-46EX720 (Panel LTY460HJ05 3D), SONY KDL-46CX520 (Panel LTY460HN01), SONY KDL-40CX521 (Panel LTY400HM07).
The appearance of the power supply
Main features of the device SONY KDL-40CX521:
Installed matrix (LCD panel) LTY400HM07.
The matrix control uses the Timing Controller (T-CON) ESP_OB_S4LV0.4.
To power the backlight used inverter SSI400_10B01.
The formation of the necessary supply voltages for all nodes of the SONY KDL-40CX521 TV is carried out by the APS-282 power module or its analogs using L6562, CXD9841P, MIP2H2 microcircuits and K15A50D type power switches.

MainBoard - the main board (motherboard) is a module 1-883-753-32, using microcircuits CXD4727GB, K4B2G1646C-HCH9, Gl850g (MN1GD07G21), KFM2GN6Q2B, SII9287BCNU PS54452, D95830, and other RTL8201.
The CXD2825GA tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: SAMSUNG
Model: LTY400HM07
Type: a-Si TFT-LCD, Panel
Diagonal size: 40 inch
Resolution: 1920x1080, FHD
Display Mode: S-PVA, Normally Black, Transmissive
Active Area: 885.6x498.15 mm
Surface: Antiglare (Haze 5.5%), Hard coating (2H)
Brightness: 420 cd / m²
Contrast Ratio: 5000: 1
Display Colors: 1.07B (8-bit + Hi-FRC), CIE1931 72%
Response Time: 12/8 (Tr / Td); 8 (G to G)
Frequency: 60Hz
Lamp Type: 10 pcs CCFL Embedded (Inverter)
Signal Interface: LVDS (2 ch, 10-bit), 51 pins
Voltage: 12.0V