Tuesday 10 March 2020

REPAIR / SERVICING TV SONY KLV-40NX500

Technical description and composition of the TV SONY KLV-40NX500, type of panel and applicable modules. The composition of the modules.
SONY LED
Model: KLV-40NX500
Chassis / Version: AZ1-A
Panel: T400HW03 v.0
T-CON: T315HW04 v.0
LED driver (backlight): VIT71880.00 rev3
Power Supply (PSU): APS-254
PWM Power: CXA3809M (PFC & PWM resonant), MIP2H2 (DIP-7 Standby)
MainBoard: BAA board A1782710A
IC MainBoard: CPU: MT5388HFMG; scaler MT5388GFMG, audio TPA3110D2, flech K9F1208UOC, DC-DC: 95503
Tuner: TEQE8-L01A
Technical Specifications KLV-40NX500
SONY KLV-40NX500
General repair guidelines for TV LCD LED
If the APS-254 power supply module fails, the external manifestations may be different, for example, the SONY KLV-40NX500 does not turn on at all and there is no indication of the control lights on the front panel. When diagnosing and repairing the power supply, first of all, replace the swollen capacitors of the filter of the secondary rectifiers and check the fuse and, if it is broken, it is necessary to identify the cause. Often in such cases, an avalanche (thermal) breakdown is detected in the power semiconductor elements of the module — rectifier diodes and transistors in the primary circuit.
Power switches in switching power supplies (SMPS) 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 MIP2H2 PWM controller chip, which can only be checked by replacing it with a new or obviously working one.
If the SONY KLV-40NX500 does not have an image, but there is sound and the TV is controlled by the remote control, a malfunction in the backlight circuits of the T400HW03 v.0 panel is likely. LEDs or their power converter - LED driver may be faulty. Often in such cases, when you turn on the TV, an image appears and immediately disappears. First of all, it is necessary to verify the operability of the electrolytic capacitors of the rectifier filter supplying the backlight assembly.
The lack of backlight often occurs due to an open circuit in the LED circuit. There is a need for disassembling the panel and checking the LEDs themselves, as well as the same contact connections in the connectors and rations of the terminals.
To open all transitions, several tens of volts or more are necessary, and it is best to use a current source for such purposes. A break in the line of LEDs connected in series cannot be detected with a multimeter or tester without disassembling the panel. In the open panel, it is necessary to check each LED. If your multimeter cannot open the LED transitions in forward bias, then see the presence of the PN transition of the protective zener diode by connecting the probes in the opposite direction. If the zener diode is broken or broken in short-circuit, then the LED is faulty and needs to be replaced.
If the BAA A1782710A motherboard is faulty, first of all it is necessary to check all the linear stabilizers and power converters of its chips, and also, if necessary, update the software (software). Sometimes you can check the health of MB only by replacement.
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: MT5388HFMG; . BGA chip malfunctions are usually easy to detect by warming up.
In the absence of tuning to the channels of on-air or cable television, you should make sure that the software is correct, as well as in accordance with the ratings of the supply voltages on the terminals of the TEQE8-L01A tuner. It is also necessary to check the presence of pulses of data exchange between the tuner and the processor via the I2C bus using an oscilloscope.
Once again, we remind TV users: you should not make attempts to repair it yourself without the appropriate knowledge, experience and the necessary qualifications! Trust the repair only to professionals with sufficient experience in the field of electronic equipment repair.


schematic manual -------------->  Sony KLV-26-32NX400 KLV-32-40NX500 Chassis AZ1-A 

KLV-26NX400, KLV-32NX400, KLV-32NX500, KLV-40NX500.

schematic manual -------------->   APS-252, APS-253, APS-254 Power supply

 The appearance of the MainBoard BAA is shown in the figure below:
BAA
BAA can be used in TVs:
SONY KLV-22BX300 (Panel T216XW01 V.3), SONY KLV-22BX301 (Panel 22 "), SONY KLV-26BX301 (Panel V260B3-L05 Rev.C1), SONY KLV-26NX400 (Panel V260B3-L05 Rev.C1), SONY KLV-32BX300 (Panel LTY320AP04), SONY KLV-32BX301 (Panel LTY320AP05 006), SONY KLV-32NX500 (Panel T315HW04 V.0), SONY KLV-40BX400 (Panel LTZ400HM01 A13), SONY KLV-40BX401 (Panel LTY400HM01 A05 ), SONY KLV-32EX300 (Panel LTY320AP04), SONY KLV-40NX500 (Panel T400HW03 v.0).
PSU Advanced
According to the conditions of compliance with modern world standards for household switching power supplies, the APS-254 module provides for the use of a Power Factor Correction unit. The PFC circuit is a flyback converter based on the CXA3809M & PWM resonant PWM controller. The reactance of an electrolytic capacitor of a line filter at a frequency of 50-60 Hz is usually not more than 20-30 ohms and its charge directly from the network through open diodes could reach tens of amperes per pulse if no filtering were applied.
As a result of the PFC conversion, an increased voltage on the capacitor (about 380V) cannot directly open the rectifier diodes, on the anode of which the voltage will always be slightly less (about 300V) and then its charging current will always be limited by the elements of the PWM controller. As a result, the envelope of the high-frequency pulses of the consumed current will repeat the shape and phase of the input sinusoidal voltage. The presence of an increased voltage (+ 380V) on the network capacitor indicates the serviceability of the PFC node.
The appearance of the power supply
Main features of the device SONY KLV-40NX500:
Installed matrix (LED-panel) T400HW03 v.0.
The matrix control uses the Timing Controller (T-CON) T315HW04.
The LED driver VIT71880.00 is used to power the backlight LEDs.
The formation of the necessary supply voltages for all nodes of the SONY KLV-40NX500 TV is carried out by the APS-254 power module, or its analogs, using CXA3809M (PFC & PWM resonant), MIP2H2 (DIP-7 Standby) microcircuits.
MainBoard - the main board (motherboard) is a BAA module using CPU chips: MT5388HFMG; scaler MT5388GFMG, audio TPA3110D2, flech K9F1208UOC, DC-DC: 95503 and others.
The TEQE8-L01A tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: AUO
Model: T400HW03 V0
Type: a-Si TFT-LCD, Panel
Diagonal size: 40 inch
Resolution: 1920x1080, FHD
Display Mode: AMVA3, Normally Black, Transmissive
Active Area: 885.6x498.15 mm
Surface: Antiglare (Haze 11%)
Brightness: 450 cd / m²
Contrast Ratio: 5000: 1
Display Colors: 16.7M (8-bit), CIE1931 72%
Response Time: 6.5 (G to G)
Frequency: 60Hz
Lamp Type: 10 pcs CCFL Embedded (Inverter)
Signal Interface: LVDS (2 ch, 8-bit), 51 pins
Voltage: 12.0V