Technical description and composition of the DEXP H24B7100E TV, type of panel and applicable modules. The composition of the modules.DEXP LED
Model: H24B7100E
Chassis / Version: CV512L-B
Panel: CX236LEDM (V236BJ1-P01)
T-CON: CM1801, CM501, CM601, 428RP (ST24C128)
LED driver (backlight): integrated into PSU; 30.5V 416mA
PWM LED driver: OB3350CP
MOSFET LED driver: AOD450
Power Supply (PSU): MP24S-CX
PWM Power: OB2273 (PWM SOT23-6)
MainBoard: CV512L-B
IC MainBoard: SPI FLESH: 25Q64C, Sound: YD1517P
Tuner: DVB-T2
Technical Specifications H24B7100
DEXP H24B7100E
General repair guidelines for TV LCD LED
Possible malfunctions
- The DEXP H24B7100E does not turn on. There are no signs of operability. The indicators on the front panel do not light or flash, the TV does not respond to the remote control and control buttons.
Most likely, in this case, the MP24S-CX main switching power supply (MPS) is faulty. It is necessary to verify the presence of its output voltages and, if they are completely absent, check the power switches and rectifier diodes for a probable short circuit.
In the event of a breakdown in the secondary circuits of the converter, it can usually fail in short circuit mode, and in the event of a short circuit in the power elements of the primary circuit, the mains fuse or current sensor at the source of the key most often breaks.
Breakdown of power switches (MosFet) in pulsed sources is sometimes caused by malfunctions of other circuit elements, for example, in circuits supplying a PWM controller, frequency-setting or damper ones, as well as in negative feedback circuits (OOS) of stabilization. PWM controllers (PWM) OB2273 (PWM SOT23-6), if they do not have visible damage to the case and open fault between the terminals, are usually checked by replacement.
- There is no image, but there is sound and reaction to the remote control. Or for a second, the image may appear immediately after switching on.
The most likely in these cases is a malfunction of the LED backlight. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
It is impossible to check the LED line for breaks without disassembling the panel with a multimeter or tester. For these purposes, it is necessary to open all series-connected PN junctions and a voltage of the order of tens of volts will be required, and ideally, a current source. Having disassembled the panel, it is necessary to check each LED separately. Chinese multimeters, as a rule, light up a single 3-volt LED in the forward direction. In the case of using dual 6-volt LEDs, the PN junction of its protective zener diode can serve as a health indicator. In faulty LEDs, the 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 CV512L-B 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 - SPI FLESH: 25Q64C, Sound: YD1517P. Defective components should be replaced.
If you suspect a malfunction of the DVB-T2 tuner, first of all, you need 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.
Once again, remind users! Attempts to independently repair a DEXP H24B7100E TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!
SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> Main CV512L-B
FIRMWARE FOR SPI FLASH -----------> DEXP H24B7100E, Main: CV512L-B, Panel: CX236LEDM (V236BJ1-P01)
The appearance of the MainBoard CV512L-B is shown in the figure below:CV512L-B
CV512L-B can be used in TVs:
BBK 28LEM-1021/T2C (Panel SV275SHD HX010403 X41), BBK 22LEM-1026/FT2C (Panel M215HGE-P02), DEXP H24B7100E (Panel CX236LEDM (V236BJ1-P01)), DEXP F22B7000E/B (Panel CX215LEDM), ERISSON 22LEE31T2 (Panel CX215LEDM), RUBIN RB-22SE2FT2S (Panel 1080p Full HD 1920x1080), SUPRA STV-LC24T880WL (Panel HV236WHB-N00), SUPRA STV-LC22T880FL (Panel LC215DTBA).
The appearance of the power supply
Key Features of the DEXP H24B7100E:
Installed matrix (LED-panel) CX236LEDM (V236BJ1-P01).
The matrix control uses the Timing Controller (T-CON) CM1801.
To power the backlight LEDs, a converter is used, combined with a power supply unit, controlled by the OB3350CP PWM controller. As power elements of the LED driver, keys of the AOD450 type are used.
The necessary supply voltages for all nodes of the DEXP H24B7100E TV are generated by the MP24S-CX power module or its analogs using OB2273 chips (PWM SOT23-6).
MainBoard - the main board (motherboard) is a CV512L-B module, using chips SPI FLESH: 25Q64C, Sound: YD1517P and others.
The DVB-T2 tuner provides television reception and channel tuning.
DEXP H24B7100 TV with CX236LEDM LCD, 24 "(61 cm) diagonal size of 16: 9 format. The required screen brightness of 300 cd / m² is provided by LED backlight LED. Contrast - the ratio of maximum brightness to minimum is 3000: 1. Dynamic contrast 176: 1 is achieved by special control of the operation of the LEDs depending on the illumination of the plots in the plot.In this model, a panel with the end position of the backlight LEDs - Edge LED is used. You can watch programs and movies and images in high quality HD At a resolution of 1366x768 pixels in the standard of graphic decomposition 720p (HD Ready). The input high-frequency or video signal is decoded in analog systems PAL, SECAM, NTSC. Graphic processing and digital signal generation occurs in standards 480i, 480p, 576i, 576p, 720p. Supported file formats multimedia: MP3, WMA, MPEG4, MKV, JPEG.
The power of the sound system 10 W (2x5 W) provides 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, 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, 1024x768, 1360x768. A digital tuner is capable of receiving television channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
Overall dimensions: with stand 560x360x180 mm, without stand 560x320x50 mm.
Mass of the TV: 3.53 kg.
Attention! The CX236LEDM (V236BJ1-P01) panel of a DEXP H24B7100 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.
