Technical description and composition of the DEXP F40B8300K TV, type of panel and applicable modules. The composition of the modules.DEXP LED
Model: F40B8300K
Chassis / Version: 882YTK
Panel: GS15-0049 p / n 72000882YTK
LED backlight: 40628 * 35021360, * 35020268 KONKA
LED driver (backlight): integrated into MainBoard
Power Supply (PSU): integrated into MainBoard
PWM Power: FAN6755
MOSFET Power: TK7P60W TO-263
MainBoard: 35021373 40QT628ANTS Rev.00
IC MainBoard: CPU: MSD6A628VXE-SW
Tuner: NoName
Control: WIFI: QINGLIA QJ-WF88RE
Technical Specifications F40B8300K
DEXP F40B8300K
General repair guidelines for TV LCD LED
Possible malfunctions
- The DEXP F40B8300K TV does not turn on, does not respond to the remote control and buttons on the control panel, does not light up or blink indicators.
In such cases, the main power source - the AC / DC voltage converter, which is combined with the MainBoard 35021373 board, may turn out to be faulty. You should measure its output voltages, and if they are absent, check the power switches of the converters and rectifier diodes for a short circuit probability.
In case of breakdowns of semiconductors in the secondary circuits of any converter, as a rule, it can operate in emergency short circuit mode without output voltages, and during short circuit in the elements of the primary circuit, the mains fuse and, less often, the current sensor at the source of the key are most often cut off.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements that can put it out of operation in key mode or provoke an excess of the maximum current or voltage. These can be circuits supplying the PWM controller, damping or frequency-setting circuits, or elements of OOS (negative feedback) in the stabilization circuit. FAN6755 PWM controllers (PWM), in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- There is no image, there is sound, it responds to the remote control. Or the image may appear for a second when turned on and immediately disappears.
As a rule, in such cases there is no display backlight. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
It should be remembered that it is not possible to determine the break in the LED lines without disassembling the panels using 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 35021373 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). When repairing an MB board, you need to check its CPU components: MSD6A628VXE-SW. Defective items should be replaced. If chips with BGA soldering technology are used, a problem in its implementation is detected by the local heating of the chip.
The failure of the NoName tuner is established after checking the software and all supply voltages at its terminals. The data exchange of the tuner with the processor via the I2C bus can be controlled by an oscilloscope.
Attention to users! Self-repair of a DEXP F40B8300K TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!
The appearance of the MainBoard 35021373 is shown in the figure below:35021373
Main features of the DEXP F40B8300K device:
Installed matrix (LED-panel) GS15-0049 p / n 72000882YTK.
To power the backlight LEDs, a converter is used, combined with the main board 35021373.
The power module is combined with the MainBoard and is designed according to the flyback AC / DC voltage converter using FAN6755 microcircuits and TK7P60W TO-263 type power switches.
MainBoard - the main board (motherboard) is a module 35021373, using CPU chips: MSD6A628VXE-SW and others.
The NoName tuner provides television reception and channel tuning.
DEXP F40B8300K TV with YTK0882 LCD, 40 "(102 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 with direct LEDs - Direct LED.The TV features include viewing programs and movies in high quality HD at a resolution of 1920x1080 pixels in a graphical decomposition according to the standard 1080p (Full HD).
F40B8300K has built-in SMART Software and pre-installed Android TV Operating System. Connecting to the Internet can be done via Wi-Fi. The input high-frequency or video signal is decoded in analog systems PAL, SECAM, NTSC. Graphic processing and digital signal generation occurs in the standards 480i, 480p, 576i, 576p, 720p, 1080i. Supported media file formats: MP3, WMA, MPEG4, MKV, JPEG.
The power of the acoustic system of sound 20 W (2x10 W) provide two speakers. It uses a NICAM stereo signal processing system and Sound Surround.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), component, VGA, HDMI x3, USB x2, Ethernet (RJ-45), Wi-Fi. 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, 1360x768. A digital tuner is capable of receiving television channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
Attention! The panel YTK0882 MT102A12I LED-TV DEXP F40B8300K 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.