Thursday, 27 August 2020

REPAIRING / SERVICING TV DNS S32DST1

Technical description and composition of the DNS S32DST1 TV, panel type and modules used. The composition of the modules.
DNS LED
Model: S32DST1
Chassis / Version: T.MSD309.BA3T
Panel: HV320WX2-201
T-CON: HV320WXC-200_X-PCB-X0.0
LED driver (backlight): integrated into PSU
PWM LED driver: PWM 8pin
Power Supply (PSU): AY066D-4SF
PWM Power: PWM SOT23-6
MOSFET Power: 6N60
MainBoard: T.MSD309.BA3T
IC MainBoard: CPU: MSD309BT, SPI Flash: 25Q32FVS1G, W631GG6KB, Audio: TPA3124D2
Specifications S32DST1
DNS S32DST1
General recommendations for TV LCD LED repair
Possible manifestations of malfunctions
- TV DNS S32DST1 does not turn on at all. No response to the remote control and front panel control buttons. Indicator lamps do not light up or flash.
Usually with similar manifestations, the defect is caused by faulty elements in the main power module AY066D-4SF. It is necessary to measure its output voltages, and in the event of their absence (full or partial), the serviceability of the power switches of the converters and rectifier diodes should be checked for a possible short circuit.
In case of diode breakdowns in the secondary circuits, the converter can operate in an emergency mode of short circuit without output voltages, and in case of a short circuit in the power elements of the primary circuit, the mains fuse and / or the current sensor in the source of the key usually breaks off.
Breakdown of Mos-Fet switches used in switching power supplies is often caused by malfunctions of other elements, for example, in the power supply circuit of the PWM controller, in frequency setting or damper circuits, as well as in negative feedback stabilization. PWM microcircuits (PWM) PWM SOT23-6 are usually checked by replacing them with new ones, or known to be working properly.
- There is no picture, but there is sound and reaction to the remote control. Or, for a second, the image may appear immediately after switching on.
Most likely in these cases is a malfunction of the LED panel backlight. The reason for this may be an open circuit in the LED circuit, or a problem in stabilizing their power supply.
To check the LED strips for breakage without disassembling the panel, for example, a current source will help. It is impossible to open series-connected PN junctions with a simple multimeter; a voltage of the order of several tens of volts is required.
- The indicator on the front panel blinks, the TV does not turn on in operating mode, does not respond to the remote control.
Repair or diagnostics of the T.MSD309.BA3T motherboard should begin with checking the stabilizers and power converters necessary to power the microcircuits and matrix. If necessary, you should update or replace the software (software). When repairing an MB board, you need to check its components CPU: MSD309BT, SPI Flash: 25Q32FVS1G, W631GG6KB, Audio: TPA3124D2. Defective elements must be replaced. If chips with BGA soldering technology are used, the problem in its implementation is detected by local heating of the chip.
Remember! Attempts to repair the DNS S32DST1 TV yourself, in the absence of the necessary qualifications and experience, are categorically not recommended and are fraught with negative consequences, up to the complete non-repairability of the device!

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Additional MainBoard Repair
The appearance of the MainBoard T.MSD309.BA3T is shown in the figure below:
T.MSD309.BA3T
T.MSD309.BA3T can be used in TVs:
DNS M39DM8 (Panel V390HJ1-P02 Rev C1), DNS S29DB1 (Panel V290BJ1-LE1), DNS S39DB1 (Panel V390HJ1-LE1), DNS V40D8200 (Panel LSC400HV02-W05), DNS M32DM8 (Panel V320BJ2-P01), DNS S32DSB1 (Panel T315HB01 V.1), DNS S32DST1 (Panel HV320WX2-201).
External view of the power supply

Main features of the DNS S32DST1 device:
Installed matrix (LED-panel) HV320WX2-201.
The matrix control uses the Timing Controller (T-CON) HV320WXC-200_X-PCB-X0.0.
To power the backlight LEDs, a converter combined with a power supply is used, controlled by a PWM 8pin PWM controller.
The formation of the necessary supply voltages for all nodes of the DNS S32DST1 TV is carried out by the AY066D-4SF power module, or its analogs using PWM SOT23-6 microcircuits and 6N60 type power switches.
MainBoard - the main board (motherboard) is a T.MSD309.BA3T module, using CPU chips: MSD309BT, SPI Flash: 25Q32FVS1G, W631GG6KB, Audio: TPA3124D2 and others.
Additional technical information about the panel:
Brand: BOE
Model: HV320WX2-201
Type: a-Si TFT-LCD, CELL
Diagonal size: 31.5 inch
Resolution: 1366x768, WXGA
Display Mode: AFFS, Normally Black, Transmissive
Active Area: 697.685x392.256 mm
Surface: Antiglare (Haze 10%), Hard coating (3H)
Glass Depth: 0.70 + 0.70 mm
Transmissivity: 6.6% (with Polarizer)
Contrast Ratio: 1200: 1
Display Colors: 16.7M (8-bit)
Response Time: 8 (G to G)
Frequency: 60Hz
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V
DNS TV S32DST1 with LCD HV320WX2-201, diagonal size 32 "(81 cm) 16: 9. The required screen brightness of 350 cd / m² is provided by LED backlighting. Contrast - the ratio of maximum to minimum brightness is 2000: 1. This model uses a panel with backlight LEDs - Edge LED.
The HV320WX2-201 sensor and MainBoard T.MSD309.BA3T software provide high quality HD viewing at a resolution of 1366x768 pixels in 720p (HD Ready). The input high-frequency or video signal is decoded in analog systems PAL, SECAM, NTSC. Graphic processing and formation of a digital signal occurs in the standards 480i, 480p, 576i, 576p, 720p, 1080i. Supported media file formats: MP3, MPEG4, DivX, MKV, JPEG.
Speaker power 16 W (2x8 W) is provided by two speakers. The NICAM STEREO audio processing system is used.
External interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, component, SCART, RGB, VGA, HDMI x4, USB. To connect a computer or laptop to this TV model, a VGA (D-Sub 15) connector on the TV case is used, this interface supports resolutions: 640x480, 800x600, 1024x768, 1360x768. The digital tuner is capable of receiving television channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
The TV uses the AY066D-4SF power supply.
Dimensions: With stand 735x490x210 mm, Without stand 735x449x65 mm.
TV weight: 7.6 kg.
Attention! The HV320WX2-201 panel of the DNS S32DST1 LED TV is an expensive and unreliable element.
Do not allow any impact on the glass and pressure on the screen surface to avoid damage to the LED panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it drips down the glass onto the cables to make the TV unrepairable.