Friday 17 April 2020

REPAIR / SERVICING TV DEXP 32A3300

Technical description and composition of the DEXP 32A3300 TV, type of panel and applicable modules. The composition of the modules.
DEXP LED
Model: 32A3300
Chassis / Version: TP.VST59S.P89
Panel: JHD315GH-E52
LED backlight: 75YYN11003-PILB67F7-E510-B-PJL
T-CON: T320XVN02.9 CTRL BD 32T24-C0C; AUO-61422, AUO-11303
LED driver (backlight): integrated into MainBoard
PWM LED driver: OB3350CP
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT23-6
MainBoard: TP.VST59S.P89
IC MainBoard: CPU: TSUMV59XES-XG, Spi Flash: W25Q32
Tuner: R620D
Specifications 32A3300
DEXP 32A3300
General repair guidelines for TV LCD LED
Possible malfunctions
- The DEXP 32A3300 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.
The malfunction in such cases, first of all, should be sought in the power elements of a switching power supply (IIP) - a network voltage converter (AC / DC), which in this TV model is combined with the main board MainBoard TP.VST59S.P89. It is necessary to measure the output voltages in its secondary circuits, and if they are completely absent, it is necessary to check the serviceability of power switches and rectifier diodes for possible breakdown (short circuit).
In the event of breakdowns 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.
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 the remote control. Or for a second, the image may appear immediately after switching on.
In some of these cases, the malfunction is caused by the lack of a backlight display. 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.
It is impossible to check the line of series-connected LEDs without a special current source, and for this purpose it is not safe to use any voltage sources above 12V for them. Then it remains only to open the panel and check each LED separately. Usually, Chinese 9V-powered multimeters light up a single 3-volt LED, if you connect the probes in the forward direction, the red probe to the anode, and the 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 turn on, does not respond to the remote control. The indicator blinks or signals standby mode.
Repair or diagnostics of the TP.VST59S.P89 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 - Cpu: TSUMV59XES-XG, Spi Flash: W25Q32. Defective components should be replaced.
If you suspect a malfunction of the R620D tuner, first of all, it is necessary to verify the correctness of the software, as well as the presence of the necessary voltage levels and impulses of data exchange with the processor via the I2C bus at the corresponding terminals of the tuner.
Owners and users of the DEXP 32A3300 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!



The appearance of MainBoard TP.VST59S.P89 is shown in the figure below:
TP.VST59S.P89
The TP.VST59S.P89 motherboard is combined with a power module and is an independent device made on the basis of the TSUMV59Xxx multifunction processor. Repair of such a board must begin by checking the power batteries, as well as the operability of voltage converters and linear stabilizers, necessary to provide power to certain processor nodes, in particular: + 1.2V core power, built-in DDR + 1.8V memory and Stand- by 3.3V. The power supply voltage of the LCD panel is 5V or 12V, depending on the type of panel used, it is necessary to check directly on the LVDS connector.
TP.VST59S.P89 can be used in TVs:
AKAI LEA-32A08G (Panel LC320EXN (SE) (E1)), AKAI LEA-28A08W (Panel ST2751A01-1), DEXP 32A3300 (Panel JHD315GH-E52), DNS H32A30 (Panel JHD315GH-E52), FUSION FLTV-32L42B (Panel KM315E3-CS-02), TELEFUNKEN TF-LED32S6 (Panel CX315DLEDM ST3151A05-5).
Main features of the DEXP 32A3300 device:
Installed matrix (LED panel) JHD315GH-E52.
The matrix control uses the Timing Controller (T-CON) T320XVN02.9.
To power the backlight LEDs, a converter is used, combined with the TP.VST59S.P89 main board, controlled by the OB3350CP PWM controller.
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 TP.VST59S.P89 module, using Cpu chips: TSUMV59XES-XG, Spi Flash: W25Q32 and others.
The R620D tuner provides TV reception and channel tuning.
A DEXP 32A3300 TV with a JHD315GH-E52 LCD, 32 "(81 cm) diagonal size of 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 3000: 1. The LCD panel uses direct pixel illumination with rear LEDs - Direct LED. You can watch broadcasts 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 the standards 480i, 480p, 576i, 576p, 720p, 1080i. Supported media file formats: MP3, MPEG4, DivX, 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, 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 735x497x180 mm, without stand 735x455x70 mm.
TV Weight: with stand: 6.35 kg, without stand: 4.9 kg.
Attention! The JHD315GH-E52 panel of a DEXP 32A3300 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.