Technical description and composition of the SONY KDL-55EX720 TV, panel type and modules used. The composition of the modules.
SONY LED
Model: KDL-55EX720
Chassis / Version: AZ2F
Panel: LTY550HJ03
LED driver (backlight): 1-883-300-11
PWM LED driver: BD9276EFV
Power Supply (PSU): APS-299 1-883-922-12 & DPS78
PWM Power: CXA3811M, CXA3799AM, MIP2H2
MOSFET Power: N-FET TO-220F
MainBoard: 1-883-753-32 Y2009380A
IC MainBoard: CXD4727GB, K4B2G1646C-HCH9, KFM2GN6Q2B, Y164B, NJU72040, Sil9287BCNU, GL850G
Tuner: CXD2825GA
Specifications KDL-55EX720
SONY KDL-55EX720
General recommendations for TV LCD LED repair
Possible malfunctions
- TV SONY KDL-55EX720 does not turn on at all. No response to the remote control and front panel control buttons. Indicator lamps do not light up or flash.
Most likely, in this case, the main switching power supply (SMPS) APS-299 is faulty. Then we recommend measuring its output voltages and, if they are absent, you should check the serviceability of the power switches (N-FET TO-220F) and the rectifier diodes of the converters for a possible short circuit.
In case of diode breakdowns in the secondary circuits, the converter can operate in an emergency mode of short circuit without output voltages, and with a short circuit in the power elements of the primary circuit, the mains fuse and / or the current sensor in the source of the key usually breaks off.
Mos-Fet power switches used in switching power supplies sometimes fail due to a malfunction of any other elements that can disable it in the key mode, or create an excess of the maximum permissible key parameters. These can be elements supplying a PWM regulator, frequency setting or damper circuits, or elements of negative feedback in the stabilization circuit. PWM controllers CXA3811M, CXA3799AM, MIP2H2, in the absence of visible damage or outright short circuits between the terminals, are checked by replacing them with new ones, or known to be working properly.
- There is no image, the screen is black, there is sound, sometimes you can see barely noticeable outlines of the image in the ambient light of the screen.
Most likely in these cases is a malfunction of the LED panel backlight. Often the cause of a malfunction is a lack of current in the LED circuit, for example, their open or short circuit, or a violation of the contact connections of the connectors of the strips.
It is impossible to detect an open circuit in the LED line without disassembling the panel with a simple multimeter. The LEDs are connected in series and a voltage of several tens of volts is required to open their junctions. Ideally, a current source is suitable for such purposes. You can open the panel and check each LED separately. Usually, Chinese multimeters lightly light up one 3-volt LED if you connect the probes to it in the forward direction (red probe to the anode, black to the cathode). For dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of the LED health. In the event of a malfunction of the LED, its zener diode will either be cut off, or broken through in the K / Z.
In cases where the SONY KDL-55EX720 does not have an image, but there is sound, the display backlight often does not work.
In LED TVs, the LEDs inside the LTY550HJ03 panel are usually faulty, and less often the LED driver.
Without backlighting, sometimes you can see a barely noticeable image with a certain successful hit of external light on the screen.
Replacing the LEDs requires disassembling the LTY550HJ03 panel. We do not recommend such works on their own to TV owners and craftsmen who do not have experience in repairing LCD panels, especially at home.
If there is no image, and the backlight is on, the screen becomes slightly lighter when turned on, and on an open TV, the light is visible through the holes in the panel case.
In this case, the T-CON (Timing Controller) board may be defective, but often the MainBoard 1-883-753-32 is also defective. A software failure is also possible. The panel can also be faulty - damage to strips, loops, for example, after moisture. In such cases, first of all, it is necessary to check the panel supply voltage at the LVDS connector, fuses on the T-CON board or panel brackets, as well as supply and reference voltages for column and line drivers - VGH, VGL, Vcom.
If they are within the normal range, then the oscilloscope must track the passage of LVDS signals from MainBoard 1-883-753-32, as well as synchronization signals to the loops with drivers.
Flooded screens of LED TVs can sometimes be restored if significant damage has not formed in the loops and on the panel trims.
- The indicator blinks or is on constantly, the TV does not turn on, does not respond to the remote control.
Repair or diagnostics of the 1-883-753-93 motherboard should begin with checking the stabilizers and power converters necessary to power the microcircuits and matrix. If necessary, you should update or replace the software (software). In some cases, to repair the MB (SSB) board, it may be necessary to replace the chips - CXD4727GB, K4B2G1646C-HCH9, SIL9287BCNU, GL850G with new or known good ones. In cases where BGA technologies are used, defects are usually localized by heating.
If there is no tuning to channels of terrestrial or cable television, you should make sure that the software is correct, as well as in accordance with the ratings of the supply voltages at the NoName tuner outputs. It is also necessary to check with an oscilloscope the presence of pulses of data exchange between the tuner and the processor via the I2C bus.
Attention to TV owners! Attempts to repair SONY KDL-55EX720 yourself are not recommended by the manufacturer and can lead to serious negative consequences!
DOWNLOAD SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> CHASSIS AZ2F FOR MODELS : KDL-32EX720, KDL-32EX721, KDL-32EX723, KDL-32EX724, KDL-32EX725,
KDL-32EX726, KDL-32EX727, KDL-32EX728, KDL-32EX729, KDL-37EX720,
KDL-37EX723, KDL-37EX725, KDL-40EX720, KDL-40EX721, KDL-40EX723,
KDL-40EX724, KDL-40EX725, KDL-40EX726, KDL-40EX727, KDL-40EX728,
KDL-40EX729, KDL-46EX720, KDL-46EX721, KDL-46EX723, KDL-46EX724,
KDL-46EX725, KDL-46EX726, KDL-46EX727, KDL-46EX728, KDL-46EX729,
KDL-55EX720, KDL-55EX721, KDL-55EX723, KDL-55EX725.
Revision after repair of the backlight. BD9276EFV in LED driver 1-883-300-11. Information from the master.
In the driver current sensors on the board 1-883-300-11, from pins 26, 28, 30, 32 of the BD9276EFV microcircuit, two 3.3 Ohm resistors per channel are installed in parallel on the case.
Reducing the backlight current from 125 mA to 95 mA - increased the value of one of the pair of resistors from 3.3 Ohm to 6.8 Ohm for each of the four above pins, leaving the other unchanged.
Driver current limitation. BD9276EFV at 1-883-300-11.
General recommendations
To reduce the backlight current in LED drivers 1-732-438-11, you should proportionally increase the values of the resistors from pins 26, 28, 30, 32 of the BD9276EFV microcircuit to ground for all four channels in the same way, for example, remove one resistor from the pair, then the current will be halved.
You can increase the value of one of the pair of resistors so as to reduce the current by 20-30 percent.
Additional MainBoard Repair
The appearance of MainBoard 1-883-753-32 is shown in the figure below:
1-883-753-32
1-883-753-32 can be used in TVs:
SONY KDL-32CX520 (Panel V315H3-L01), SONY KDL-32EX421 (Panel LTY320AN02), SONY KDL-32EX720 (Panel LTY320HJ01), SONY KDL-40EX521 (Panel LTY400HM08 001), SONY KDL-46EX720 (Panel LTY460HJ05 3D), SONY KDL-46CX520 (Panel LTY460HN01), SONY KDL-40CX521 (Panel LTY400HM07).
External view of the power supply
APS-299:
APS-299
Main features of the SONY KDL-55EX720 device:
The matrix (LED-panel) LTY550HJ03 is installed.
The LED driver 1-883-300-11 is used to power the backlight LEDs, it is controlled by the PWM controller BD9276EFV.
The formation of the necessary supply voltages for all nodes of the SONY KDL-55EX720 TV is carried out by the APS-299 power module, or its analogs using CXA3811M, CXA3799AM, MIP2H2 microcircuits and N-FET TO-220F power switches.
MainBoard - the main board (motherboard) is a 1-883-753-32 module, using chips CXD4727GB, K4B2G1646C-HCH9, KFM2GN6Q2B, Y164B, NJU72040, Sil9287BCNU, GL850G and others.
The CXD2825GA tuner provides reception of television programs and tuning to channels.
Instructions and updates
Bravia TVs: Firmware download version 4.027:
PKG4.027EUA file, version 4.027 dated 12/11/2014 (70,578,347 bytes).
For models: KDL-65HX920, KDL-65HX923, KDL-65HX925, KDL-60NX720, KDL-60NX723, KDL-60NX725, KDL-55EX720, KDL-55EX721, KDL-55EX723, KDL-55EX725, KDL-55NX720, KDL-55NX723, KDL-55NX725, KDL-55HX820, KDL-55HX823, KDL-55HX825, KDL-55HX920, KDL-55HX923, KDL-55HX925, KDL-46CX520, KDL-46CX525, KDL-46EX520, KDL-46EX521, KDL-46EX524, KDL-46EX525, KDL-46EX720, KDL-46EX721, KDL-46EX723, KDL-46EX724, KDL-46EX725, KDL-46EX726, KDL-46EX727, KDL-46EX728, KDL-46EX729, KDL-46HX720, KDL-46HX723, KDL-46HX725, KDL-46NX720, KDL-46NX723, KDL-46NX725, KDL-46HX820, KDL-46HX823, KDL-46HX825, KDL-46HX920, KDL-46HX923, KDL-46HX925, KDL-40CX520, KDL-40CX521, KDL-40CX523, KDL-40CX525, KDL-40EX520, KDL-40EX521, KDL-40EX523, KDL-40EX524, KDL-40EX525, KDL-40EX720, KDL-40EX721, KDL-40EX723, KDL-40EX724, KDL-40EX725, KDL-40EX726, KDL-40EX727, KDL-40EX728, KDL-40EX729, KDL-40HX720, KDL-40HX723, KDL-40HX725, KDL-40NX720, KDL-40NX723, KDL-40NX725, KDL-37EX521, KDL-37EX524, KDL-37EX525, KDL-37EX720, KDL-37EX723, KDL-37EX725, KDL-32CX520, KDL-32CX521, KDL-32CX523, KDL-32CX525, KDL-32EX421, KDL-32EX425, KDL-32EX520, KDL-32EX521, KDL-32EX523, KDL-32EX524, KDL-32EX525, KDL-32EX720, KDL-32EX721, KDL-32EX723, KDL-32EX724, KDL-32EX725, KDL-32EX726, KDL-32EX727, KDL-32EX728, KDL-32EX729, KDL-26EX320, KDL-26EX321, KDL-26EX325, KDL-24EX320, KDL-24EX325, KDL-22EX320, KDL-22EX325.
The update file and instructions can be downloaded from the manufacturer's website for the KDL-55EX720.
Guides and instructions are also offered for this model:
User manual. Published on 26 Apr 2017, size 6.55 MB.
i-Manual. Published on 13 Apr 2014.
SONY KDL-55EX720 TV with LCD LTY550HJ03, 55 "(140 cm) diagonal, 16: 9 format. This model uses Edge LED side illumination.
There is support for 3D images with active (shutter) separation technology of the right and left channels.
The LTY550HJ03 sensor and MainBoard 1-883-753-32 software provide viewing of broadcasts and movies in high quality HD at a resolution of 1920x1080 pixels in graphics decomposition at 1080p (Full HD).
The KDL-55EX720 TV is equipped with SMART software, built-in applications and the ability to work on the Internet. Internet connection can be made via Wi-Fi wireless connection. The input analog video signal can be processed in PAL, SECAM, NTSC systems. Graphic processing and formation of a digital signal picture occurs in the standards 480i, 480p, 576i, 576p, 720p, 1080i, 1080p. Video processor supported media file formats: MP3, WMA, MPEG4, Xvid, DivX, MKV, JPEG.
The power of the sound speaker system is 20 W (2x10 W), provided by two speakers. Uses the NICAM stereo signal processing system and the Sound Surround function.
External interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, audio x2, component, SCART, RGB, VGA, HDMI x4, USB x2, Ethernet (RJ-45). A headphone output is provided. To connect an analog computer or laptop to this TV model, a VGA (D-Sub 15) connector is used, which supports resolutions: 640x480, 800x600, 1024x768, 1280x1024, 1360x768, 1920x1080. The digital tuner is capable of receiving TV channels in DVB-T, DVB-C standards.
The power consumed when operating from the mains is 113 W. Power supply 1-883-922-12.
Dimensions: with stand 1269x799x315 mm, without stand 1269x769x41 mm.
TV weight: with stand: 25.4 kg, without stand: 20.2 kg.
Attention! The panel LTY550HJ03 of the SONY KDL-55EX720 LED TV the most precious element of it.
Avoid impacts on the glass and excessive pressure on the screen surface to avoid damage to the LED panel!
It is unsafe for any liquid to spill on the screen. Sometimes one drop of water is enough, if it flows down the glass onto the plumes, the TV may become unrepairable. (SO YOU HAVE TO SPRAY YOUR JIZZ SOMEWAY OFF YOUR DUMB GARBAGE TV)
