Technical description and composition of the DEXP F55D7000E TV, type of panel and applicable modules. The composition of the modules.DEXP LED
Model: F55D7000E
Chassis / Version: CV512H-A50
Panel: CX550DLEDM
LED backlight: CX55D13-ZC21FG-05 303CX550050
T-CON: TT5461B07-3-C-1; CSF11, 5562A, i1991
LED driver (backlight): integrated into MainBoard
PWM LED driver: LD5530
MOSFET LED driver: 7N65
Power Supply (PSU): integrated into MainBoard
PWM Power: L6562, LD5530
MOSFET Power: 13N50, 7N65
MainBoard: CV512H-A50
IC MainBoard: SPI FLASH: 25Q64, AUDIO: TPA3110LD2, AS358M
Tuner: CDT-9NT372-RF01
Technical Specifications F55D7000E
DEXP F55D7000E
General repair guidelines for TV LCD LED
Possible manifestations of defects
- The DEXP F55D7000E TV does not turn on and does not show any signs of turning on, it does not respond to the control buttons or to the remote control.
In such cases, the main power source, the AC / DC voltage converter, which is combined with the MainBoard CV512H-A50, may turn out to be faulty. It is necessary to measure its output voltages and, in case of their absence, check the serviceability of power switches (13N50, 7N65) and rectifier diodes in the converters for possible breakdown.
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.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, in the power supply circuit of a PWM controller, in frequency-setting or damping circuits, as well as in Negative Stabilization Feedback. PWM chips L6562, LD5530 are usually checked by replacing with new, or obviously working.
- There is no image, the screen is black, there is sound, with external illumination of the screen, you can sometimes see barely noticeable outlines of the image.
In some of these cases, the malfunction is caused by a lack of backlighting on the display. Often the cause is a malfunction of the LEDs (open circuit, short circuit ...), or the connectors of the strips (strings), less often the LED driver is malfunctioning.
It should be remembered that it is not possible to determine the open circuit in the LED lines without disassembling the panels with a tester or multimeter without an additional device, for example, a current source. To open all PN junctions connected in series at once, a voltage of several tens of volts may be required. Then it is necessary to open the panel and check each LED separately with a multimeter. If the capabilities of your multimeter do not allow you to open the LED in the forward direction or dual LEd are used, then the PN junction of the emergency zener diode can indirectly serve as a health indicator. In case of LED-a failure, the zener diode PN junction 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 CV512H-A50 motherboard should begin by checking the stabilizers and power converters needed to power the chips and matrix. If necessary, update or replace the software (software). In some cases, to repair the MB (SSB) board, it may be necessary to replace the chips - SPI FLASH: 25Q64, AUDIO: TPA3110LD2, AS358M with new or obviously working ones. In cases where BGA technologies are used, defects are usually localized by the heating method.
If the TV works normally from external devices, but does not tune into television channels, the tuner CDT-9NT372-RF01 may be malfunctioning. In such cases, first of all, you should make sure that there are supply voltages at its corresponding conclusions. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus. Sometimes the cause of the inoperability of the tuner may be a software failure.
Owners and users of the DEXP F55D7000E TV should remember that self-repair without special knowledge, skills and qualifications can be fraught with negative consequences that can lead to complete non-repairability of the device!
SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> Power supply INTEGRATED into CV512H-A50
FIRMWARE FOR SPI FLASH -----------> DEXP F55D7000E, Main: CV512H-A50, Panel: CX550DLEDM
Reduce backlight current :.The panel has 78 LEDs of 3 volts. Current 571 mA.
If you remove the 4.7 Ohm resistor in the current sensor, the current will be 518 mA, if you remove the 3.9om current, 498 mA.
Repair MainBoard
The appearance of the MainBoard CV512H-A50 is shown in the figure below:
CV512H-A50
Main features of the DEXP F55D7000E device:
Installed matrix (LED-panel) CX550DLEDM.
The matrix control uses the Timing Controller (T-CON) TT5461B07-3-C-1 ;.
To power the backlight LEDs, a converter is used, combined with the main board CV512H-A50, controlled by the LD5530 PWM controller. As power elements of the LED driver, keys of the 7N65 type are used.
The power module is combined with the MainBoard and is made according to the flyback AC / DC voltage converter circuit using L6562, LD5530 microcircuits and 13N50, 7N65 type power switches.
MainBoard - the main board (motherboard) is a CV512H-A50 module, using microchips SPI FLASH: 25Q64, AUDIO: TPA3110LD2, AS358M and others.
The tuner CDT-9NT372-RF01 provides the reception of television programs and tuning to channels.
A DEXP F55D7000E TV with a CX550DLEDM LCD, diagonal size 54.6 "(139 cm), 16: 9 format. The required screen brightness of 280 cd / m² is provided by LED backlighting. Contrast - the ratio of maximum brightness to minimum is 4000: 1. In LCD -panels use direct LED backlighting with direct LEDs - Direct LED.The TV features include viewing programs and movies in high quality HD at a resolution of 1920x1080 pixels in graphic resolution according to the standard 1080p (Full HD). Supported file formats mul Media: MP3, WMA, MPEG4, DivX, MKV, JPEG.
The power of the sound speaker system 16 W (2x8 W) is provided by two speakers. The audio processing system NICAM STEREO is used.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, audio x2, component, VGA, HDMI x3, USB. An output for connecting headphones is provided. A digital tuner is capable of receiving television channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
The power consumed by the TV working in the network mode is 135 watts.
Overall dimensions: with stand 1247x782x265 mm, without stand 1247x723x81 mm.
TV Weight: with stand: 15.3 kg, without stand: 14.3 kg.
Attention! The CX550DLEDM panel of a DEXP F55D7000E LED TV is an expensive and unreliable element.
Avoid any impact on the glass and pressure on the surface of the screen to avoid damage to the LED panel!
It is also unsafe to get liquid on the screen. Sometimes one drop is enough if it flows down the glass onto the cables so that the TV becomes unrepairable.
