Saturday 7 March 2020

REPAIR / SERVICING TV SONY KDL-40HX800

Technical description and composition of the SONY KDL-40HX800 TV, panel type and applicable modules. The composition of the modules.
SONY LED
Model: KDL-40HX800
Chassis / Version: AZ1-L
Panel: LTY400HL02
T-CON: 3496D-TQL_C4LV0.3. LJ94-03496D
LED driver (backlight): integrated into PSU
PWM LED driver: CXD9969P
MOSFET LED driver: TK8A50D
Power Supply (PSU): APS-265 (CH) 1-882-224-11
PWM Power: MIP2H2 (Stb), CXA3809AM
MOSFET Power: TK15A50D
MainBoard: 1-881-636-41
IC MainBoard: CPU: MC10161F1-420, AUDIO: TAS5707
Tuner: SUT-HE111T
Technical Specifications KDL-40HX800
SONY KDL-40HX800
General repair guidelines for TV LCD LED
Possible malfunctions
- The SONY KDL-40HX800 TV does not turn on at all. The control lights do not light or flash. The TV on the remote control and the control panel buttons do not respond.
With such manifestations, in some cases, the APS-265 power module is faulty. It is necessary to measure the output voltages in its secondary circuits, and if they are completely absent, check the serviceability of the power switches (TK15A50D) and rectifier diodes for possible breakdown (short circuit).
In case of any breakdown of semiconductors in the secondary circuits, the converter can usually work normally in emergency short circuit mode. There are no output voltages. And with a short circuit in the power elements of the primary circuit, as a rule, the mains fuse breaks and less often the current sensor at the source of the key.
Breakdown of power switches (MosFet) in pulsed sources is sometimes caused by malfunctions of other circuit elements, for example, in circuits supplying a PWM controller, frequency-setting or damper ones, as well as in negative feedback (OOS) stabilization circuits. PWM controllers (PWM) MIP2H2 (Stb), CXA3809AM, if they do not have visible damage to the case and open fault between the terminals, 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.
Often in such cases, there is no LED backlight. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
It is impossible to check the line of series-connected LEDs without a special current source, and for this purpose it is not safe to use any voltage sources above 12V for them. Then it remains only to open the panel and check each LED separately. Usually, Chinese 9V-powered multimeters light up a single 3-volt LED, if you connect the probes in the forward direction, the red probe to the anode, and the black to the cathode. In dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of health. In the event of a LED malfunction, its zener diode will either be cut off or broken into short-circuit.
- 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 1-881-636-41 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). Sophisticated MB board repair (SSB) is in some cases possible and practiced by repairmen. To do this, check and, if necessary, replace the CPU elements: MC10161F1-420, AUDIO: TAS5707. BGA chip malfunctions are usually easy to detect by warming up.
Before replacing the SUT-HE111T tuner, if there is no tuning to the channels, you must first check the software and the supply voltage at its terminals. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus
Attention to users! Self-repair of a SONY KDL-40HX800 TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!


Service manual / schematic diagram ------------->   SONY KDL-40HX800 Chassis AZ1-L

 The appearance of MainBoard 1-881-636-41 is shown in the figure below:
1-881-636-41
The appearance of the power supply
Main features of the device SONY KDL-40HX800:
Installed matrix (LED-panel) LTY400HL02.
The matrix control uses the Timing Controller (T-CON) 3496D-TQL_C4LV0.3 ..
To power the backlight LEDs, a converter is used, combined with a power supply unit, controlled by a CXD9969P PWM controller. As the power elements of the LED driver, keys of the TK8A50D type are used.
The necessary supply voltages for all nodes of the SONY KDL-40HX800 TV are generated by the APS-265 power module or its analogs using MIP2H2 (Stb), CXA3809AM microcircuits and TK15A50D type power switches.
MainBoard - the main board (motherboard) is a module 1-881-636-41, using CPU chips: MC10161F1-420, AUDIO: TAS5707 and others.
The SUT-HE111T tuner allows you to receive television programs and tune to channels.
Additional technical information about the panel:
Brand: SAMSUNG
Model: LTY400HL02
Type: a-Si TFT-LCD, Panel
Diagonal size: 40 inch
Resolution: 1920x1080, FHD
Display Mode: Normally Black, Transmissive
Lamp Type: WLED