Technical description and composition of the TV SONY KDL-40BX420, type of panel and applicable modules. The composition of the modules.SONY
Model: KDL-40BX420
Chassis / Version: AZ2EK_P-2F
Panel: LTZ400HM02 A04
Inverter (backlight): SSI400 10B01 - REV: 1.0
PWM Inverter: SSI091ASN
MOSFET Inverter: MDD1752 BP052HGG
Trans Inverter: CT400S34.T400S32
Power Supply (PSU): APS-284 - 1-883-776-21 - 147431011 G14
PWM Power: MIP2H2, CXA3810
MOSFET Power: 9NK50 kK5A50
MainBoard: MT66_EU - S0100-2 EB1C23
IC MainBoard: MT5135, STA3698WS, PS331
Tuner: SUT-RE205TN
Control: RM-ED046
Technical Specifications KDL-40BX420
SONY KDL-40BX420
General recommendations for repairing TV LCD
Repair of a SONY KDL-40BX420 TV is advisable to start with an external inspection of all its constituent elements, both internal electronic components and external. Inspection is also subject to body elements, control buttons, screen, connectors and cords. Often, by the external signs and nature of some damage, it is possible to draw preliminary conclusions and determine a further algorithm for troubleshooting. Ring cracks in the soldering of the leads of the heating elements, swollen electrolytic capacitors, a charred paint layer on the resistors - all this for the repairman can be a hint in assumptions about the causes and consequences of the malfunction.
In cases when the SONY KDL-40BX420 TV does not turn on, does not respond to the remote control and buttons, any indicators on the front panel do not light up or blink, and there are no sounds and no signs of operability at all, the power supply module G14 147431011 is most likely faulty or , which is much less common - there is no processor power on the motherboard. It is advisable to start the troubleshooting of the power supply module by checking the mains fuse. If it is broken, it is necessary to check first of all the power semiconductor elements - rectifier diodes and the power switch of the 9NK50 kK5A50 converter, which are often found in breakdown conditions in such situations.
As a rule, the keys of flyback converters, which use the N-Fet field effect transistor on a separate radiator, or integrated with the MIP2H2 PWM controller in a single chip, are reliable enough and rarely fail for no reason. The reasons for the breakdown of the key should be sought 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 the power module uses an active KKM circuit (power factor control), troubleshooting is somewhat more complicated.
In cases where the SONY KDL-40BX420 TV has lost an image, and the sound is there and all other functions are operational, there is a possibility of an inverter (converter for powering the backlight) malfunction. When you turn on the TV, the image may appear briefly and immediately disappear. It must be borne in mind that with such manifestations, the lamps themselves also fail, the malfunction of which can be detected by replacement, by connecting to the connectors for diagnostics that are known to be serviceable and suitable in power.
Diagnosis and repair of the inverter is often complicated by the organization of special protection circuits, which is necessary for fire safety and turns off the inverter in any emergency situation, for example, when the lamps are worn or depressurized. Often, to localize a defect, its blocking is required.
In such cases, special care should be taken during diagnostics, and after completion of all repair work, it is necessary to restore the circuit and the inverter protection for further safe operation of the TV.
If the EB1C23 motherboard is faulty, first of all it is necessary to check all the linear power regulators of its chips and, if necessary, update the software. Sometimes you can check the health of MB only by replacement. When repairing an MB board, you must check its components u17 STA36. u3: MT5135. u8060: PS331. Defective items should be replaced.
If the TV works normally from external devices, but does not tune into television channels, the tuner SUT-RE205TN may be malfunctioning. In such cases, first of all, you should make sure that there are supply voltages at its corresponding terminals, as well as the power supply of varicaps (30-33V).
We recommend the owners of the KDL-40BX420 TV for repair only to qualified specialists with experience! Self-repair attempts without the appropriate knowledge and skills can lead to serious negative consequences!
Service manual / schematic diagram -------------> Sony KDL-26BX320, KDL-26BX321, KDL-32BX320, KDL-32BX321, KDL-32BX420, KDL-37BX420, KDL-40BX420 Chassis AZ2EK P-2F
Service manual / schematic diagram -------------> Sony KDL-32BX320, KDL-32BX321, KDL-32BX420, KDL-32BX421, KDL-40BX420, KDL-40BX421, KDL-46BX420, KDL-46BX421 Chassis AZ2-UK
PSU / schematic diagram -------------> Sony APS-284 Delta Power Supply
The appearance of the MainBoard MT66_EU is shown in the figure below:MT66_EU
MT66_EU can be used on TVs:
SONY KDL-32BX320 (Panel T315XW03 V.E), SONY KDL-32BX420 (Panel T315HW04 V.C), SONY KDL-40BX420 (Panel LTZ400HM02 A04), SONY KDL-42EX410 (Panel LC420EUN (SD)(V4)), SONY KDL-32EX310 (Panel LC320EXN (SD)(A3)), SONY KDL-26BX320 (Panel T260XW04 V.7).
The appearance of the power supply
Main features of the device SONY KDL-40BX420:
Installed matrix (LCD panel) LTZ400HM02 A04.
To power the backlight, an SSI400 inverter is used, it is controlled by the SSI091ASN PWM controller. The transformer CT400S34.T400S32 is installed in the inverter converter. As power elements of the inverter, keys of the type MDD1752 BP052HGG are used.
The necessary supply voltages for all nodes of the SONY KDL-40BX420 TV are generated by the APS-284 power module or its analogs using MIP2H2, CXA3810 microchips and power switches of the 9NK50 kK5A50 type.
MainBoard - the main board (motherboard) is an MT66_EU module, using MT5135, STA3698WS, PS331 and others.
The SUT-RE205TN tuner provides television reception and channel tuning.
Additional technical information about the panel:
Brand: S-LCD
Model: LTZ400HM02
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
Lamp Type: WLED
