Technical description and composition of the TV SONY KDL-40W653A, type of panel and applicable modules. The composition of the modules.SONY LED
Model: KDL-40W653A
Panel: T420HVF04.0 xxxxG
LED backlight: 74.42T31.002-0-DX1 13212D - T42-40-R & T42-40-L.
LED driver (backlight): ST420AU-4S01 REV1.0
Power Supply (PSU): Adapter
MainBoard: 1-888-154-11 173416911 A1923812A + A1926974A
Tuner: A1929539A
Control: Remote: ST420AU-4S01 REV1.0, IR: 1-887-030-32
Appearance
SONY KDL-40W653A
General repair guidelines for TV LCD LED
Possible malfunctions
- The SONY KDL-40W653A TV does not turn on at all. There is no reaction to the remote control and control buttons from the front panel. Indicator lights do not light or flash.
Failure in such cases should begin to look in the adapter power supply circuits.
This TV model is equipped with an external adapter type power supply, which the owner can purchase independently, and repairing it may not always be advisable, however, sometimes there is a certain sense to open it and eliminate simple typical defects typical of IPS. It is necessary to verify the presence of its output voltages and, if they are completely absent, check the power switches and rectifier diodes for a probable short circuit.
In case of breakdowns in the secondary circuits, the converter, as a rule, can emergency work in the short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse usually breaks.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements that can put it out of operation in key mode or provoke an excess of the maximum current or voltage. These can be circuits supplying the PWM controller, damping or frequency-setting circuits, or elements of OOS (negative feedback) in the stabilization circuit. PWM controllers (PWM), in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- There is no image, but there is sound, it reacts to the remote control. Or the image appears when you turn it on and immediately disappears
In most of these cases, a malfunction is detected in the nodes and backlight elements of the LED panel. The reason can be both in the power supply of the LEDs, in their serviceability (breakdown or breakage), as well as in the violation of the contact connections of the LED strips.
It is impossible to detect a break in the LED line without disassembling the panel with a simple multimeter. The LEDs are connected in series and to open their transitions, a voltage of several tens of volts is required. Ideally, a current source is suitable for such purposes. You can open the panel and check each LED separately. Typically, Chinese multimeters light up a single 3-volt LED, if you connect the probes in the forward direction to it (red probe to the anode, 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 blinks or glows constantly, the TV does not turn on, does not respond to the remote control.
Repair or diagnostics of the motherboard 1-888-154-11 should begin by checking the stabilizers and power converters needed to power the microcircuit and matrix. If necessary, update or replace the software (software).
Before replacing the A1929539A tuner, if there is no tuning to the channels, 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
Once again, remind users! Attempts to self-repair a SONY KDL-40W653A TV without the appropriate qualifications and necessary experience can lead to its complete non-repairability!
The appearance of MainBoard 1-888-154-11 is shown in the figure below:1-888-154-11
Main features of the device SONY KDL-40W653A:
Installed matrix (LED-panel) T420HVF04.0 xxxxG.
The LED driver ST420AU-4S01 is used to power the backlight LEDs.
To power all the internal components of the SONY KDL-40W653A TV, an external adapter type source is used.
MainBoard - the main board (motherboard) is a module 1-888-154-11.
The tuner A1929539A provides the reception of television programs and tuning to channels.