Saturday 7 March 2020

REPAIR / SERVICING TV SONY KDL-40EX653

Technical description and composition of the TV SONY KDL-40EX653, type of panel and applicable modules. The composition of the modules.
SONY LED
Model: KDL-40EX653
Chassis / Version: BAPS mainboard
Panel: LTY400HM10
T-CON: LQF6041T0B-Q1, RT6905, I7939A
LED driver (backlight): integrated into PSU
PWM LED driver: CXA3834M
MOSFET LED driver: MDHT3N40, STPS20LCD45C
Power Supply (PSU): APS-322 1-886-370-12 GL4
PWM Power: MIP2H2 (Standby), CXA3810M
MOSFET Power: TK5A50D, TK12A50D, TK8A50D
MainBoard: 1-885-388-51 (173308951) BAPS
IC MainBoard: CXD4727GB, K4B2G1646C-HCH9, KFM4G16Q4B, SIL9287BCNU, GL850G, D2826ER, TPA6138, PS54425
Technical Specifications KDL-40EX653
SONY KDL-40EX653
General repair guidelines for TV LCD LED
Possible malfunctions
- SONY KDL-40EX653 does not turn on and does not show any signs of operability. Does not blink indicators and does not respond to control buttons.
With such manifestations, the APS-322 power module is often faulty. Then you should measure its output voltages and, if they are completely absent, you need to check the health of all power switches (TK5A50D, TK12A50D, TK8A50D) and rectifier diodes for a possible short circuit.
In the event of breakdowns in the secondary circuits, the converter may emergencyly operate in the short circuit mode, and in the event of a short circuit in the power elements of the primary circuit, the mains fuse usually breaks.
The Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other circuit elements that can put it out of operation in key mode or cause the maximum current or voltage to be exceeded. It can be supply, damper circuits, or elements of OOS (negative feedback) stabilization. The reason for the breakdown of the power switch may be PWM (PWM) MIP2H2 (Standby), CXA3810M. It is usually checked by replacing it with a new or obviously working one.
- There is no image, there is sound, it responds to the remote control, the channels are switched. In some cases, the image appears when you turn on and immediately disappears.
A malfunction is usually most likely in these cases at the backlight nodes of the display matrix. 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 1-885-388-51 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). Complex repair of MB (SSB) is possible only in the conditions of a service center with the necessary equipment. Checking or replacing elements CXD4727GB, K4B2G1646C-HCH9, KFM4G16Q4B, SIL9287BCNU, GL850G, D2826ER, TPA6138, PS54425 requires the necessary training and professional skills in repairing modules at the component level. Problems associated with the use of BGA soldering technologies can sometimes be diagnosed by warming up.

Attention to users! Self-repair of a SONY KDL-40EX653 TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!




The appearance of MainBoard 1-885-388-51 is shown in the figure below:
1-885-388-51
1-885-388-51 can be used in TVs:
SONY KDL-46HX853 (Panel FQLR460LT01 A-1853-359-B), SONY KDL-40EX653 (Panel LTY400HM10), SONY KDL-40HX853 (Panel FQLR400LT01), SONY KDL-55HX753 (Panel LTY550HQ04), SONY KDL-46HX753 (Panel LTY460HQ05).
The appearance of the power supply
Main features of the device SONY KDL-40EX653:
Installed matrix (LED-panel) LTY400HM10.
The matrix control uses the Timing Controller (T-CON) LQF6041T0B-Q1.
To power the backlight LEDs, a converter is used, combined with a power supply, controlled by a CXA3834M PWM controller. As power elements of the LED driver, keys of the type MDHT3N40, STPS20LCD45C are used.
The necessary supply voltages for all nodes of the SONY KDL-40EX653 TV are generated by the APS-322 power module or its analogs using MIP2H2 (Standby), CXA3810M microcircuits and power switches of the type TK5A50D, TK12A50D, TK8A50D.
MainBoard - the main board (motherboard) is a module 1-885-388-51, using microcircuits CXD4727GB, K4B2G1646C-HCH9, KFM4G16Q4B, SIL9287BCNU, GL850G, D2826ER, TPA6138, PS54425 and others.
Additional technical information about the panel:
Brand: SAMSUNG
Model: LTY400HM10
Type: a-Si TFT-LCD, Panel
Diagonal size: 40 inch
Resolution: 1920x1080, FHD
Display Mode: S-PVA, Normally Black, Transmissive
Active Area: 885.6x498.15 mm
Surface: Antiglare (Haze 0.8%), Hard coating (2H)
Brightness: 470 cd / m²
Contrast Ratio: 5000: 1
Display Colors: 1.07B (8-bit + Hi-FRC)
Response Time: 8 (G to G)
Frequency: 60Hz
Lamp Type: 2 strings WLED Without Driver
Signal Interface: LVDS (2 ch, 10-bit), 51 pins
Voltage: 12.0V