Technical description and composition of the DEXP F22B7000C TV, panel type and applicable modules. The composition of the modules.DEXP LED
Model: F22B7000C
Chassis / Version: JUC7.820.00123739
Panel: CX215LEDM
LED backlight: EDGE LED
LED driver (backlight): integrated into MainBoard
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT23-6
MainBoard: JUC7.820.00123739 HLT57EJ
IC MainBoard: SPI FLASH: W25Q64
Tuner: NoName
Technical Specifications F22B7000C
DEXP F22B7000C
General repair guidelines for TV LCD LED
Possible malfunctions
- The DEXP F22B7000C TV does not turn on and does not show any signs of turning on, it does not respond to the control buttons or the remote control.
In such cases, the main power source, the AC / DC voltage converter, which is combined with the MainBoard JUC7.820.00123739, may turn out to be faulty. It is necessary to measure its output voltages, and in case of their absence (full or partial), it is necessary to check the serviceability of the power switches of the converters and rectifier diodes for the presence of a possible short circuit.
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 main fuse and, less often, the current sensor at the source of the key are most often cut off.
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 SOT23-6 PWM chips are usually checked by replacing with new ones, or obviously working.
- 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 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 trying to detect a break in the LED lines, it should be taken into account that it is difficult to do this without disassembling the panel. For example, a current source is needed to open PN junctions connected in series.
- 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 JUC7.820.00123739 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). Complex repair of MB (SSB) is possible only in the conditions of a service center with the necessary equipment. Checking or replacing FLASH elements: W25Q64 requires the necessary training and professional skills to repair modules at the component level. Problems associated with the use of BGA soldering technologies can sometimes be diagnosed by warming up.
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! For users and owners of F22B7000C TVs who do not have the appropriate qualifications, knowledge and experience, we strongly recommend against attempting self-repair in order to avoid negative consequences that could lead to complete non-repairability of the device.
FIRMWARE FOR SPI FLASH -----------> DEXP F22B7000C, Main: JUC7.820.00123739 HLT57EJ, Panel: CX215LEDM
The appearance of the MainBoard JUC7.820.00123739 is shown in the figure below:
JUC7.820.00123739
Main features of the DEXP F22B7000C device:
Installed matrix (LED-panel) CX215LEDM.
A converter is used to power the backlight LEDs, combined with the main board JUC7.820.00123739.
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.
MainBoard - the main board (motherboard) is a JUC7.820.00123739 module, using SPI FLASH chips: W25Q64 and others.
The NoName tuner provides television reception and channel tuning.
DEXP F22B7000C TV with CX215LEDM LCD, diagonal size 22 "(56 cm) in 16: 9 format. The required brightness of the screen is 300 cd / m² LED backlight LED. Contrast - the ratio of maximum brightness to minimum is 1000: 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 The channel is decoded in analogue systems PAL, SECAM, NTSC. Graphic processing and digital signal generation occurs in the standards 480i, 480p, 576i, 576p, 720p. Supported media file formats: MP3, WMA, MPEG4, MKV, JPEG.
The power of the sound system 6 W (2x3 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, 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, 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 500x360x140 mm, without stand 500x320x50 mm.
TV Weight: with stand: 3.53 kg, without stand: 3 kg.
Attention! The CX215LEDM panel of a DEXP F22B7000C 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.