Technical description and composition of the DEXP F40D7200C TV, type of panel and applicable modules. The composition of the modules.DEXP LED
Model: F40D7200C / W
Chassis / Version: JUC7.820.00194894
Panel: C400F17-E63-C
LED driver (backlight): integrated into MainBoard
PWM LED driver: SOT23-6 (UB1)
MOSFET LED driver: TO-252
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT23-6
MOSFET Power: TO-252
MainBoard: JUC7.820.00194894 HLS80JS 2017-7-7
IC MainBoard: CPU: MSD3663LSA-005N, SPI Flash: 25Q64CS10
Tuner: ST18WM-2K-E
Technical Specifications F40D7200C
DEXP F40D7200C
General repair guidelines for TV LCD LED
Possible malfunctions
- The DEXP F40D7200C TV does not turn on, does not respond to the remote control and the control panel buttons, 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 JUC7.820.00194894 board, may turn out to be faulty. In the absence of the necessary supply voltages in the secondary circuits of the converters, it is necessary to check the power switches (TO-252) and rectifier diodes for a possible partial or complete breakdown.
In case of breakdowns in the secondary circuits, the converter, as a rule, can emergency work in the short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse usually breaks.
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. PWM controllers (PWM) PWM SOT23-6, in the absence of external damage and short circuit between the terminals, are checked by replacing with obviously good ones.
- There is no image, the screen is black, there is sound, with external illumination of the screen, you can sometimes see faint outlines of the image.
In most of these cases, a malfunction is detected in the nodes and backlight elements of the LED panel. The reason may be a break in the LEDs, in the stabilization of their power supply, or in the violation of the contact connections of the thong connectors,
It is impossible to detect a break in the LED line without disassembling the panel with a simple multimeter. The LEDs are connected in series and to open their transitions, a voltage of several tens of volts is required. Ideally, a current source is suitable for such purposes. You can open the panel and check each LED separately. Typically, Chinese multimeters light up a single 3-volt LED, if you connect the probes in the forward direction to it (red probe to the anode, 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 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 JUC7.820.00194894 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). If it is not possible to replace the MB (SSB) card, you need to check the health of its elements - CPU: MSD3663LSA-005N, SPI Flash: 25Q64CS10. Defective components should be replaced.
If you suspect a malfunction of the ST18WM-2K-E tuner, first of all, it is necessary to verify the correctness of the software, as well as the presence of the necessary voltage levels and pulses of data exchange with the processor via the I2C bus at the corresponding terminals of the tuner.
Attention to users! Self-repair of a DEXP F40D7200C TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!
FIRMWARE FOR SPI FLASH -----------> DEXP F40D7200C, Main: JUC7.820.00194894, Panel: C400F17-E63-C
The appearance of the MainBoard JUC7.820.00194894 is shown in the figure below:JUC7.820.00194894
Main features of the DEXP F40D7200C device:
The matrix (LED panel) C400F17-E63-C is installed.
To power the backlight LEDs, a converter is used, combined with the main board JUC7.820.00194894, controlled by the PWM controller SOT23-6 (UB1). As power elements of the LED driver, keys of the TO-252 type are used.
The power module is combined with the MainBoard and is made according to the flyback AC / DC voltage converter circuit using PWM SOT23-6 microcircuits and TO-252 type power switches.
MainBoard - the main board (motherboard) is a JUC7.820.00194894 module, using CPU chips: MSD3663LSA-005N, SPI Flash: 25Q64CS10 and others.
The ST18WM-2K-E tuner provides television reception and channel tuning.
Technical description
DEXP F40D7200C TV with C400F17-E63-C LCD, 40 "(102 cm) diagonal size of 16: 9 format. The required screen brightness of 250 cd / m² is provided by LED backlighting. Contrast - the ratio of maximum brightness to minimum is 3500: 1. The LCD panel uses direct pixel illumination with rear LEDs - Direct LED. timedia: MP3, MPEG4, HEVC (H.265), MKV, JPEG.
The power of the sound speaker system 16 W (2x8 W) is provided by 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. 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 65 watts.
Overall dimensions: with stand 906x579x204 mm, without stand 906x520x87 mm.
TV Weight: with stand: 6.8 kg, without stand: 6.5 kg.
Attention! The C400F17-E63-C panel of a DEXP F40D7200C 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