Friday 17 April 2020

REPAIR / SERVICING TV DEXP 29A3000

Technical description and composition of the DEXP 29A3000 TV, type of panel and applicable modules. The composition of the modules.
DEXP LED
Model: 29A3000
Chassis / Version: CV59SH-E32
Panel: CX290DLEDM // V290BJ1-XC01
LED backlight: EDGE LED
T-CON: V290BJ1-XC01; CM1801B, CM501, CM601, P2003EV6, GT4128
LED driver (backlight): integrated into MainBoard
PWM LED driver: BIT3267
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT23-6
Mainboard: CV59SH-E32
IC MainBoard: CPU: TSUM59XUS, SPI FLASH: GD25Q32, Audio: APA2614
Tuner: NoName RDA5156
Specifications 29A3000
DEXP 29A3000
General repair guidelines for TV LCD LED
Possible malfunctions
- The DEXP 29A3000 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 common power source is often faulty - an AC / DC voltage converter, which is combined with the elements of the CV59SH-E32 main board. 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 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.
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 (OOS) stabilization circuits. PWM controllers (PWM) PWM SOT23-6, if they do not have visible damage to the case and open short circuit between the terminals, are usually checked by replacement.
- There is no image, there is sound, it is responding to the remote control. Or immediately after turning on for a second, the image may appear and immediately disappear.
Usually in such cases, a malfunction is detected in the backlight nodes of the LED panel. 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 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 on the front panel blinks, the TV does not turn on in the operating mode, it does not respond to the remote control.
Repair or diagnostics of the CV59SH-E32 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 board (SSB), you need to check the health of its elements - CPU: TSUM59XUS, SPI FLASH: GD25Q32. Defective components should be replaced.
Before replacing the NoName tuner, if there is no tuning to the channels, you must first check the software and the supply voltage at its terminals. You also need to make sure that the tuner and processor can exchange data via the I2C bus
Once again, we remind TV users: you should not make attempts to repair it yourself without the appropriate knowledge, experience and the necessary qualifications! Entrust repair to professionals with sufficient experience in the field of repair of electronic equipment.

FIRMWARE FOR SPI FLASH  ----------->   DEXP 29A3000, Main: CV59SH-E32, Panel: CX290DLEDM.

FIRMWARE FOR SPI FLASH  ----------->   DEXP 29A3000, Main: CV59SH-E32, Panel: V290BJ1-XC01 / CX290DLEDM


 The appearance of the MainBoard CV59SH-E32 is shown in the figure below:
CV59SH-E32
CV59SH-E32 can be used in TVs:
DEXP 29A3000 (Panel CX290DLEDM), DEXP 32A3400 (Panel CX315DLEDM), DEXP 28A3100 (Panel CX275DLEDM), RUBIN RB-32SE9 (Panel CX315DLEDM).
Main features of the DEXP 29A3000 device:
Installed matrix (LED-panel) CX290DLEDM or V290BJ1-XC01.
The matrix control uses the Timing Controller (T-CON) V290BJ1-XC01 ;.
To power the backlight LEDs, a converter is used, combined with the CV59SH-E32 main board, controlled by the BIT3267 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 CV59SH-E32 module, using CPU chips: TSUM59XUS, SPI FLASH: GD25Q32, Audio: APA2614 and others.
The tuner NoName RDA5156 provides the reception of television programs and tuning to channels.
Technical description
DEXP 29A3000 TV with a CX290DLEDM LCD display, diagonal size 29 "(74 cm) in 16: 9 format. The required brightness of the screen is 250 cd / m² LED backlight LED. Contrast - the ratio of maximum brightness to minimum is 1000: 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 generation of a digital signal descends into standards 480i, 480p, 576i, 576p, 720p, 1080i Supported multimedia file formats:. MP3, WMA, MPEG4, DivX, 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, 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, 1360x768.
Attention! The CX290DLEDM panel of a DEXP 29A3000 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.