Friday 6 March 2020

REPAIR / SERVICING TV SONY KDL-32W705B

Technical description and composition of the SONY KDL-32W705B TV, panel type and applicable modules. The composition of the modules.
SONY LED
Model: KDL-32W705B
Chassis / Version: RB2G
Panel: T320HVF04.0 xxxxG
LED backlight: 74.32T41.OO1-0-DX1 (T32-30-R & T32-30-L)
LED driver (backlight): 14STM320AD-4S01 Rev1.0
PWM LED driver: BD9422EFV
MOSFET LED driver: STU30N01
Power Supply (PSU): Adapter 19.5V 4A
MainBoard: 1-889-202-12 173457412 A1998262B
IC MainBoard: CXD4748GB, CXD4743GB, TC58NVG3S0FTAI0, YDA179-S, SiI9589CTUC, RTL8201FR
Tuner: 1-889-203-12 173457512 Y400A860B
Control: RM-ED060, RM-ED061, Wi-fi: J20H076 & J20H077, Wi-fi: J20H076 and J20H077
Technical Specifications KDL-32W705B
SONY KDL-32W705B
General repair guidelines for TV LCD LED
Possible malfunctions
- SONY KDL-32W705B does not turn on, the indicators on the front panel do not light and do not blink. The TV does not respond to the control buttons and the remote control.
In most of these cases, a malfunction can be detected in the power module — the adapter.
The owner of the TV can purchase an external power supply unit such as Adapter and repairing it is not always advisable. In any case, the simplest typical defects characteristic of most IIP schemes can be easily detected and eliminated after opening. It is then necessary to measure 19.5V at the output, and in case of its absence, you should check the power switches and rectifier diodes of the converters for a short circuit probability.
In case of breakdowns in the secondary circuits, the converter can operate in a short circuit mode, and during a short circuit in the 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 the excess of maximum current or voltage values. It can be supply, damper circuits, or elements of OOS (negative feedback) stabilization. The reason for the breakdown of the power key can be PWM (PWM), which is usually checked by replacing a known-good one.
- There is no image, but there is sound and reaction to the remote control. Or for a second, the image may appear immediately after switching on.
Usually in such cases, a malfunction is detected in the backlight nodes 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 lights constantly, the TV does not turn on, does not respond to the remote control.
Repair or diagnostics of the 1-889-202-12 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). In some cases, to repair the MB board (SSB), it may be necessary to replace the chips - CXD4748GB, CXD4743GB, TC58NVG3S0FTAI0, YDA179-S, SiI9589CTUC, RTL8201FR with new or obviously working ones. In cases where BGA technologies are used, defects are usually localized by the heating method.
Before changing the tuner 1-889-203-12 173457512 Y400A860B, if it is not possible to tune to television channels, make sure that there are supply voltages that must be measured at the corresponding terminals of the tuner and check the software for correctness. The pulses of the data exchange of the tuner with the processor can be controlled by an oscilloscope
Attention TV owners! Self-repair attempts by SONY KDL-32W705B are not recommended by the manufacturer and can lead to serious negative consequences!


Service manual / schematic diagram -------------------> SONY Chassis RB2G ; MODEL KDL-32W700B, KDL-42W700B, KDL-42W800B, KDL-50W700B, KDL-55W790B, KDL-32W705B, 32W705B, KDL-42W705B, 42W705B, KDL-42W805B, KDL-50W790B, 50W790B, KDL-55W800B, KDL-32W706B, KDL-42W706B, KDL-42W807B, KDL-50W800B, KDL-55W805B, KDL-32W707B, KDL-42W707B, 42W707B, KDL-42W815B, KDL-50W805B, KDL-55W808B, 55W808B, KDL42W817B, KDL-50W807B, KDL-55W815B, KDL-42W828B, KDL-50W808B, KDL-55W817B, KDL-42W829B, KDL-50W815B, KDL-55W828B, KDL-50W817B, KDL-55W829B, KDL-50W828B, KDL-55W855B, KDL-50W829B, KDL-55W857B


 The appearance of MainBoard 1-889-202-12 is shown in the figure below:
1-889-202-12
1-889-202-12 can be used in TVs:
SONY KDL-42W706B KDL-42W706W (Panel T420HVF06.1), SONY KDL-40W605B (Panel NS4S400DND01 4-528-221-02), SONY KDL-48W585B (Panel LSY480HN01-A03), SONY KDL-32W705B (Panel T320HVF04.0 xxxxG), SONY KDL-50W705B (Panel T500HVF04.2).
Main features of the device SONY KDL-32W705B:
Installed matrix (LED-panel) T320HVF04.0 xxxxG.
The LED driver 14STM320AD-4S01 is used to power the backlight LEDs, it is controlled by the BD9422EFV PWM controller. As power elements of the LED driver, keys of the STU30N01 type are used.
To power all the internal components of the SONY KDL-32W705B TV, an external adapter type 19.5V 4A is used.
MainBoard - the main board (motherboard) is a module 1-889-202-12, using microchips CXD4748GB, CXD4743GB, TC58NVG3S0FTAI0, YDA179-S, SiI9589CTUC, RTL8201FR and others.
The tuner 1-889-203-12 173457512 Y400A860B provides reception of television programs and tuning to channels.