Saturday 7 March 2020

REPAIR / SERVICING TV SONY KDL-40S2010

Technical description and composition of the SONY KDL-40S2010 TV, panel type and applicable modules. The composition of the modules.
SONY
Model: KDL-40S2010
Chassis / Version: WAX2
Panel: LTZ400WS-L02 // LTZ400WS-L020T07
T-CON: 400WSC4LV0.4 - LJ94-01070H
Inverter (backlight): PCB2676 A06-126268 F // PCB2677 A06-126269
Power Supply (PSU): 1-869-027-12 - A1169591D - G2
PWM Power: MIP2H2 (Standby), CXD9841M, FA5500A (PFC)
MainBoard: 1-869-850-12 - 172723012 - A-1144-539-B
IC MainBoard: LM393DT, MB91305, BD9775FV
Tuner: 1-869-657-11 - 172714611 - I1173184A
Technical Specifications KDL-40S2010
SONY KDL-40S2010
General recommendations for repairing TV LCD
Repair of electronic equipment usually begins with an external inspection of the device and diagnosis of the malfunction. In this case, you should visually carefully examine all the elements of the SONY KDL-40S2010 TV, both internal and external. Often, for certain external signs, the repairman can draw some conclusions about the reasons for the failure of certain elements of the circuit even before the necessary measurements are made, which will determine the further algorithm for troubleshooting and localizing the defect. In most cases, the repairman can guess the causes of the defect and possible consequences from the characteristic signs of typical TV defects, for example, ring cracks formed in the soldering of the element leads, swollen rectifier filter capacitors, charred resistors and other circuit elements.
Sometimes the SONY KDL-40S2010 TV simply does not turn on. No control lights on the front panel are lit or blinking, the TV does not respond to the remote control and does not make any sounds or any signs of life when turned on. The most likely cause of the malfunction is a failure of the common power module. In this case, the diagnosis and repair of the common power supply should always be started by checking the mains fuse. When it breaks, it is advisable to check for a breakdown, first of all, all power semiconductor elements of the converter and the rectifier diode bridge of the network, as well as the large electrolytic filter capacitor of the network rectifier and the key transistor.
Power switches in flyback converters fail extremely rarely for no reason and, if they are broken, it is necessary to look for a malfunction in the stabilization circuits by checking electrolytic capacitors, semiconductor devices, and resistors in the primary circuit. The cause may be a malfunction of the PWM controller chip, which can only be checked by replacing it with a new or obviously working one.
When using a power factor correction unit (PFC) in the power modules, troubleshooting becomes somewhat more complicated and requires additional experience and knowledge of their operation.
In cases where the SONY KDL-40S2010 TV has lost an image, and the sound is there and all the 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.
When repairing the inverter PCB2676 A06-126268 F // PCB2677 A06-126269, it is often necessary to disable the protection for diagnostics, which, for the purpose of fire safety, turns it off in any emergency situation, for example, during a malfunction or uneven wear of the lamps, which makes it difficult to find a defect.
In such cases, the risk of failure of the power elements of the inverter is most likely, and special care is required during work, and after their completion, it is necessary to restore the protection circuit for further safe operation of the TV by the owner in normal mode.
It should be remembered! Attempts to repair the SONY KDL-40S2010 TV, in the absence of the necessary qualifications and experience, are categorically not recommended and are fraught with negative consequences, up to the complete non-repairability of the device!


Service manual / schematic diagram ------------------>   Sony KDL-23S2010, KDL-26S2010, KDL-32S2010, KDL-40S2010, KDL-46S2010 CHASSIS WAX2

 
Service manual / schematic diagram ------------------>   Sony KDL-26S2000, KDL-32S2000, KDL-40S2000, KDL-46S2000, KDL-26S2010, KDL-32S2010, KDL-40S2010, KDL-46S2010, KDL-26S2020, KDL-32S2020 CHASSIS WAX2

 The appearance of MainBoard 1-869-850-12 is shown in the figure below:
1-869-850-12
1-869-850-12 can be used on TVs:
SONY KDL-40S2000 (Panel LTY400WS-L02), SONY KDL-40S2010 (Panel LTZ400WS-L02 ).
PSU Advanced
The KDL-40S2010 TV has a power module 1-869-027-12 installed using the PFC (Power Factor Correction) scheme acting as an active filter to eliminate the higher harmonic components of the current consumption. The boost converter based on the FA5500A PWM controller does not allow the input rectifier filter's electrolytic capacitor to be connected to the network directly through open diodes, when the value of the charge current determines its reactance (about 15-30 ohms at a frequency of 50 Hz). As a result of the conversion, the charging current of the capacitor will be determined in such a way that the envelope of the high-frequency pulses of the input current will repeat the phase and shape of the sine wave of the input voltage. The health check of the PFC unit is carried out by measuring the DC voltage on the capacitor of the rectifier network. In operating mode, it should be around 380V, in standby approximately 300V.
The appearance of the power supply
Main features of the device SONY KDL-40S2010:
Installed matrix (LCD panel) LTZ400WS-L02 or LTZ400WS-L020T07.
The matrix control uses the Timing Controller (T-CON) 400WSC4LV0.4.
A PCB2676 inverter is used to power the backlight.
The necessary supply voltages for all nodes of the SONY KDL-40S2010 TV are generated by the power module 1-869-027-12, or its analogs using microchips MIP2H2 (Standby), CXD9841M, FA5500A (PFC).
MainBoard - the main board (motherboard) is a module 1-869-850-12, using microchips LM393DT, MB91305, BD9775FV and others.
Tuner 1-869-657-11 - 172714611 - I1173184A provides the reception of television programs and tuning to channels.