Monday 20 April 2020

REPAIR / SERVICING TV DEXP H32B3100E

Technical description and composition of the DEXP H32B3100E TV, panel type and applicable modules. The composition of the modules.
DEXP LED
Model: H32B3100E
Chassis / Version: TP.VST59S.PB816
Panel: CX315DLEDM
LED backlight: ZDCX32D10-ZC21F-01
T-CON: V320BJ7-PE1
LED driver (backlight): integrated into MainBoard
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT23-6
MainBoard: TP.VST59S.PB816
IC MainBoard: TSMUV59XUS-Z1, MX25L3205
Tuner: NoName
Control: IR: CQG50421 200.CXR-LE32D90-0H
Technical Specifications H32B3100E
DEXP H32B3100E
General repair guidelines for TV LCD LED
Possible malfunctions
- The DEXP H32B3100E TV 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.
First of all, in such cases, you should verify the operability of the common switching power supply (IIP) - AC / DC voltage converter of the mains voltage. All source elements in this TV model are located on the MainBoard TP.VST59S.PB816 main board. 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 during 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 SOT23-6 PWM chips are usually checked by replacing with new ones, or obviously working.
- There is no image, but there is sound and reaction to commands from the remote control. Or the image appears immediately after turning on and disappears.
Usually in such cases, a malfunction is detected in the backlight nodes of the LED panel. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
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 TP.VST59S.PB816 motherboard should begin by checking the stabilizers and power converters needed to power the microcircuits and matrix. If necessary, update or replace the software (software). In some cases, to repair the MB board (SSB), it may be necessary to replace the chips - TSMUV59XUS-Z1, MX25L3205 with new or obviously good ones. In cases where BGA technologies are used, defects are usually localized by the heating method.
In cases where there is no tuning to the channels of on-air or cable television, you should make sure that the software is correct, as well as in accordance with the ratings of the supply voltage at the outputs of the NoName tuner. It is also necessary to check the presence of pulses of data exchange between the tuner and the processor via the I2C bus using an oscilloscope.
TV users and owners must remember that attempts to self-repair a DEXP H32B3100E TV without the appropriate qualifications and the necessary experience can lead to serious negative consequences!

FIRMWARE FOR SPI FLASH  ----------->   DEXP H32B3100E, Main: TP.VST59S.PB816, Panel: CX315DLEDM

 The appearance of MainBoard TP.VST59S.PB816 is shown in the figure below:
TP.VST59S.PB816
Main features of the DEXP H32B3100E device:
Installed matrix (LED-panel) CX315DLEDM.
The matrix control uses the Timing Controller (T-CON) V320BJ7-PE1.
To power the backlight LEDs, a converter is used, combined with the main board TP.VST59S.PB816.
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 module TP.VST59S.PB816, using chips TSMUV59XUS-Z1, MX25L3205 and others.
The NoName tuner provides television reception and channel tuning.
A DEXP H32B3100E TV with a CX315DLEDM LCD display, a 32 "(81 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 3000: 1. Is Possible viewing broadcasts and films 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 comes in 480i standards, 480p, 576i, 576p, 720p Supported multimedia file formats:. MP3, WMA, MPEG4, DivX, MKV, JPEG.
The power of the acoustic system of sound 20 W (2x10 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 x2, 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, 1360x768.
Overall dimensions: with stand 735x477x230 mm, without stand 735x440x88 mm.
TV Weight: with stand: 4.5 kg, without stand: 4.69 kg.
Attention! The CX315DLEDM panel of a DEXP H32B3100E 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.