Technical description and composition of the DEXP 50A7100 TV, panel type and applicable modules. The composition of the modules.DEXP LED
Model: 50A7100
Chassis / Version: JUC7.820.00123921
Panel: C500F13-E2-A
T-CON: TT-5550T15C04
LED driver (backlight): integrated into PSU
Power Supply (PSU): MP165D-1MF21
MainBoard: JUC7.820.00123921
IC MainBoard: 25Q64
Tuner: CH-DMI21-C816RH
Specifications 50A7100
DEXP 50A7100
General repair guidelines for TV LCD LED
Possible malfunctions
- The DEXP 50A7100 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 some of these cases, a malfunction is detected in the MP165D-1MF21 power supply module. Then it is necessary to measure its output voltages and, in case of their complete or partial absence, it is necessary to check the serviceability of power switches and rectifier diodes of the converters for a possible short circuit.
In case of any breakdown of semiconductors in the secondary circuits, the converter can usually work normally in emergency short circuit mode. There are no output voltages. And with a short circuit in the power elements of the primary circuit, as a rule, the mains fuse breaks and less often the current sensor at the source of the key.
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 microcircuits are usually checked by replacement with new ones, or obviously working.
- There is no image, there is sound, it responds to the remote control, the channels are switched. In some cases, the image appears when you turn on and immediately disappears.
Often in such cases, there is no LED backlight. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
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 turn on, does not respond to the remote control. The indicator blinks or signals standby mode.
Repair or diagnostics of the JUC7.820.00123921 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 attempts to repair the MB board (SSB), it is necessary to check the serviceability of its elements - 25Q64 which may require replacement with new ones. If a BGA processor is installed, there is a possibility of a violation of the soldering of the contacts of its conclusions with the board (it is diagnosed by heating).
If there is no reception of television channels, but the TV is working properly from external devices, first of all, check the voltage of the tuner CH-DMI21-C816RH and update the software. The pulses from the I2C bus must be controlled with an oscilloscope.
Owners and users of the DEXP 50A7100 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!
FIRMWARE FOR SPI FLASH -----------> DEXP 50A7100, Main: JUC7.820.00123921, Panel: C500F13-E2-A
The appearance of the power supply
Main features of the DEXP 50A7100 device:
Installed matrix (LED-panel) C500F13-E2-A.
The matrix control uses the Timing Controller (T-CON) TT-5550T15C04.
To power the backlight LEDs, a converter is used, combined with a power supply.
The formation of the necessary supply voltages for all nodes of the DEXP 50A7100 TV is carried out by the MP165D-1MF21 power supply module, or its analogs.
MainBoard - the main board (motherboard) is a JUC7.820.00123921 module, using 25Q64 chips and others.
The CH-DMI21-C816RH tuner provides TV reception and channel tuning.
DEXP 50A7100 TV with C500F13-E2-A LCD, 50 "(127 cm) diagonal size of 16: 9 format. The required screen brightness of 330 cd / m² is provided by LED backlighting. Contrast - the ratio of maximum brightness to minimum is 3000: 1. The LCD panel uses direct pixel illumination with rear LEDs - Direct LED.The 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 the channel 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, DivX, MKV, JPEG .
The power of the speaker system of sound 8 W (2x4 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, S-Video, component, VGA, HDMI x3, USB x2. 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 1116x690x226 mm, without stand 1116x645x60 mm.
TV Weight: with stand: 16.5 kg, without stand: 16 kg.
Attention! The C500F13-E2-A panel of a DEXP 50A7100 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.