Technical description and composition of the DEXP 40A7000 TV, type of panel and applicable modules. The composition of the modules.DEXP LED
Model: 40A7000
Chassis / Version: JUC7.820.00108763
Panel: C400F13-E2-C
LED backlight: RF-AB400E32-1001S-01 A7
T-CON: V390HJ1-XRME1 & V390HJ5-XCPE1
LED driver (backlight): integrated into MainBoard
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT-23-6
MainBoard: JUC7.820.00108763 // TP.S512.PB83
IC MainBoard: MSD308BT-SW, MSB101A, H5TQ1G63EFR, GD25Q64BSIG, TPA3110D2
Tuner: DT21WN-2A-E
Control: IR: JUC7.820.00081814
Specifications 40A7000
DEXP 40A7000
General repair guidelines for TV LCD LED
Possible malfunctions
- The DEXP 40A7000 TV does not turn on, does not respond to the remote control and the control panel buttons, the indicators do not light or flash.
Most often, with such manifestations, the power source, which is combined with the MainBoard, turns out to be faulty. In the absence of the necessary supply voltages in the secondary circuits of the converters, it is necessary first of all to check the power switches and rectifier diodes for a possible partial or complete 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, power supply, frequency-setting, damper ... as well as elements of the Negative Stabilization Feedback. The PWM SW-23-6 PWM chip 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, it reacts to the remote control. Or the image appears when you turn it on and immediately 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.
When diagnosing, it is necessary to take into account that it is impossible to check the open in the chain of LED lines without disassembling the panels using a tester or multimeter. To open all PN junctions connected in series, a voltage of the order of several tens of volts is required, and ideally, a current source. By opening the panel, each LED can be checked separately. Typically, Chinese multimeters light up a single 3-volt LED, if you connect probes in the forward direction to it. 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 indicator blinks or lights constantly, the TV does not turn on, does not respond to the remote control.
Repair or diagnostics of the JUC7.820.00108763 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 cases of complex repairs of MB (SSB) and in the presence of the necessary skills and equipment, sometimes it may be necessary to replace its chips MSD308BT-SW, MSB101A, H5TQ1G63EFR, GD25Q64BSIG, TPA3110D2 and other possible faulty components. Malfunctions associated with the application of BGA soldering technologies are usually easily diagnosed by the heating method.
Before changing the DT21WN-2A-E tuner, if it is not possible to tune to television channels, make sure that there are supply voltages that must be measured at the corresponding tuner terminals and checked for correctness. The pulses of the data exchange of the tuner with the processor can be controlled by an oscilloscope
TV users and owners should remember that attempts to self-repair a DEXP 40A7000 TV without the appropriate qualifications and necessary experience can lead to serious negative consequences!
FIRMWARE FOR SPI FLASH -----------> DEXP 40A7000, Main: JUC7.820.00108763, Panel: C400F13-E2-C
FIRMWARE FOR SPI FLASH -----------> DEXP 40A7000, Main: TP.S512.PB83, Panel: C400F13-E2-C(G2)
There is version 40A7000 (China) - MainBoard: TP.S512.PB83, Panel C400F13-E2-C, T-Con: V390HJ5-XCPE1 V400HJ6-PE1 REV. C1.
Repair MainBoard
The appearance of the MainBoard JUC7.820.00108763 is shown in the figure below:
JUC7.820.00108763
JUC7.820.00108763 can be used in TVs:
DEXP 40A7000 (Panel C400F13-E2-C), DEXP 32A3200 (Panel C320X13-E7-H).
Main features of the DEXP 40A7000 device:
Installed matrix (LED-panel) C400F13-E2-C.
The matrix control uses the Timing Controller (T-CON) V390HJ1-XRME1.
A converter is used to power the backlight LEDs, combined with the main board JUC7.820.00108763.
The power module is combined with MainBoard and is made according to the flyback AC / DC voltage converter circuit using PWM SOT-23-6 microcircuits.
MainBoard - the main board (motherboard) is a JUC7.820.00108763 module, using microchips MSD308BT-SW, MSB101A, H5TQ1G63EFR, GD25Q64BSIG, TPA3110D2 and others.
Tuner DT21WN-2A-E provides the reception of television programs and tuning to channels.
DEXP 40A7000 TV with C400F13-E2-C LCD, 40 "(102 cm) diagonal size 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. Dynamic contrast ratio of 5000: 1 is achieved by special control of the LEDs depending on the illuminance of the plot in the plot.The LCD panel uses direct pixel illumination with rear LEDs - Direct LED. in high quality HD at a resolution of 1920x1080 pixels in graphic decomposition according to the standard 1080p (Full HD). 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, 1080p Supported media file formats: MP3, WMA, MPEG4, MKV, JPEG.
The power of the sound system 16 W (2x8 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, audio x2, component, VGA, HDMI x3, 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 906x566x210 mm, without stand 906x520x93 mm.
TV Weight: with stand: 8.2 kg, without stand: 7.85 kg.
Attention! The C400F13-E2-C panel of a DEXP 40A7000 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.