Technical description and composition of the DEXP F55B7000T TV, panel type and applicable modules. The composition of the modules.DEXP LED
Model: F55B7000T
Chassis / Version: MSD6308-T8E
Panel: K550WD7
LED backlight: 4708-K550WD-A3213K21 Typ-B / A
T-CON: 6870C-0471D
LED driver (backlight): integrated into PSU
Power Supply (PSU): K-PL-L03 465R1029SDJB
PWM Power: IC_Power
MainBoard: MSD6308-T8E 20140123 A2 4704-6308T8-A2233K01
IC MainBoard: MSD6308RTEC-SW, 9F2G08ABAEA
Technical Specifications F55B7000T
DEXP F55B7000T
General repair guidelines for TV LCD LED
Possible malfunctions
- The DEXP F55B7000T TV does not turn on and does not show any signs of operability. There is no reaction to either the remote control or the control buttons from the front panel.
Typically, with such manifestations, the defect is caused by faulty elements in the K-PL-L03 module. It is necessary to measure the secondary output voltage, and in case of their absence, check the serviceability of the power switches of the converters and rectifier diodes for a short circuit.
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, power supply, frequency-setting, damper ... as well as elements of the Negative Stabilization Feedback. PWM IC_Power may also cause a malfunction of the power switch of the converter and is checked by replacement.
- There is no image, but there is sound and reaction to commands from the remote control. Or the image appears immediately after turning on and disappears.
Often in such cases, there is no LED backlight. The reason can be both in the power supply of the LEDs, in their serviceability (breakdown or breakage), as well as in the violation of the contact connections of the LED strips.
To check the LED strips, to open all the transitions of the LEDs, several tens of volts or more are needed, it is best to use a current source for such purposes. The breakage of several PN junctions connected in series cannot be detected with a multimeter or tester. In such cases, it is necessary to open the panel and check each LED. If your multimeter cannot open the LED transitions in forward bias, you can sometimes detect the presence of a PN junction 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.
- The TV does not enter the operating mode, does not respond to the remote control. The indicator on the front panel lights constantly or blinks.
Repair or diagnostics of the motherboard MSD6308-T8E should begin by checking the stabilizers and power converters needed to power the chips and matrix. If necessary, update or replace the software (software). Often, the MB (SSB) card must be replaced in case of complex malfunctions that are difficult to detect. When trying to repair, you should check its elements - MSD6308RTEC-SW, 9F2G08ABAEA and replace failed chips with new ones. Some malfunctions may be due to the use of BGA soldering technologies in modern Main Board technologies. Typically, such defects are detected by local heating of the chip.
TV users and owners need to remember that attempts to self-repair a DEXP F55B7000T TV without the appropriate qualifications and necessary experience can lead to serious negative consequences!
The appearance of the MainBoard MSD6308-T8E is shown in the figure below:MSD6308-T8E
MSD6308-T8E can be used in TVs:
DEXP F42B7000T (Panel K420WD7), DEXP F55B7000T (Panel K550WD7).
The appearance of the power supply
Main features of the DEXP F55B7000T device:
Installed matrix (LED-panel) K550WD7.
The matrix control uses the Timing Controller (T-CON) 6870C-0471D.
To power the backlight LEDs, a converter is used, combined with a power supply.
The necessary supply voltages for all nodes of the DEXP F55B7000T TV are generated by the K-PL-L03 power module, or its analogs using IC_Power microcircuits.
MainBoard - the main board (motherboard) is an MSD6308-T8E module, using microchips MSD6308RTEC-SW, 9F2G08ABAEA and others.
DEXP F55B7000T TV with K550WD7 LCD, 55 "(140 cm) diagonal size of 16: 9 format. The required screen brightness of 300 cd / m² is provided by LED backlighting. Contrast - the ratio of maximum brightness to minimum is 3500: 1. In LCD - panels use direct LED backlighting - Direct LED. TV features include viewing programs and movies in high quality HD at a resolution of 1920x1080 pixels in the graphic resolution of the standard 1080p (Full HD). Input high-frequency or video signal al decoded into analog PAL system, SECAM, NTSC Image processing and the formation of the digital signal is in 480i standards, 480p, 576i, 576p, 720p, 1080i, 1080p Supported multimedia file formats:.. MP3, WMA, MPEG4, MKV, JPEG.
The power of the acoustic system of sound 20 W provide 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, component, VGA, HDMI x3, MHL, USB. An output for connecting headphones is provided. To connect a computer or laptop to this TV model, a VGA (D-Sub 15) connector is used on the TV case, this interface supports resolutions: 640x480, 800x600, 1024x768, 1280x1024, 1360x768, 1920x1080. A digital tuner is capable of receiving television channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
Overall dimensions: with stand 1250x800x290 mm,.
TV Weight: 15 kg.
Attention! The K550WD7 panel of a DEXP F55B7000T 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.