Thursday, 27 August 2020

REPAIRING / SERVICING TV DNS S32DSB1

Technical description and composition of the DNS S32DSB1 TV, panel type and modules used. The composition of the modules.
DNS LED
Model: S32DSB1
Chassis / Version: T.MSD309.BA5T
Panel: T315HB01 V.1
LED backlight: 73.31T14.004-5-DS1 40 LEDs 361mm 31T14-07A
T-CON: T460HW03 VF CTRL BD
LED driver (backlight): T315HW07 V8 LED DRIVER BD 31T14-D06
PWM LED driver: MAX16814
Power Supply (PSU): MD-F075-0322 (F0014-BE06)
MainBoard: T.MSD309.BA5T // T.MSD309.BA3T
IC MainBoard: CPU: MSD309BT, SPI Flash: 25Q32FVS1G, W631GG6KB, Audio: TPA3124D2
S32DSB1 Specifications
DNS S32DSB1
General recommendations for TV LCD LED repair
Possible manifestations of malfunctions
- TV DNS S32DSB1 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.
In some of these cases, the main switching power supply, the MD-F075-0322 module, is faulty. Then you should measure its output voltages and, in case of their complete or partial absence, it is necessary to check the serviceability of the power switches and rectifier diodes of the converters 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) are usually checked by replacing them with new ones, or knowingly working.
- There is no image, there is sound, it reacts to the remote control. Or, immediately after switching on for a second, the image may appear and immediately disappear.
The malfunction in most of such cases is found in the nodes and elements 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.
When diagnosing, it must be borne in mind that it is impossible to check for an open in the circuit of the LED lines without disassembling the panels using a tester or multimeter. To open all PN junctions connected in series, a voltage of the order of several tens of volts is required, and ideally a current source. By opening the panel, you can check each LED separately. Typically, Chinese multimeters will lightly light one 3-volt LED if you connect the probes to it in the forward direction. For dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of the LED health. In the event of a malfunction of the LED, its zener diode will either be cut off, or broken through in the K / Z.
- The TV does not turn on, does not respond to the remote control. The indicator blinks or signals the standby mode.
Repair or diagnostics of the T.MSD309.BA5T motherboard should begin with checking the stabilizers and power converters required to power the microcircuits and matrix. If necessary, you should update or replace the software (software). Complicated repair of MB (SSB) board is in some cases possible and practiced by repairmen. To do this, check and, if necessary, replace elements 25Q32FVS1G, W631GG6KB. Malfunctions in BGA chips are usually easy to detect by warm-up.

To reduce the backlight current in LED drivers with a MAX16814 PWM controller (TSSOP20 MAX16814B), the total resistance of the resistors from pin 10 (SETI) to the package must be proportionally increased. The maximum current in each of the four channels (in milliamperes) for the resistance Rseti (in kilo-ohms) is determined from the ratio 1500 / Rseti.

Attention to users! Self-repair of the DNS S32DSB1 TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!



DOWNLOAD FIRMWARE FOR SPI FLASH  ----------->   DNS S32DSB1, Main: T.MSD309.BA5T,


DOWNLOAD FIRMWARE FOR SPI FLASH  ----------->   DNS S32DSB1, Main: T.MSD309.BA3T, Panel: T315HB01 V.1



 DOWNLOAD SCHEMATIC DIAGRAM  / SERVICE MANUAL   ------------------>    Chassis MSD309B Schematic diagram

 The appearance of the MainBoard T.MSD309.BA5T is shown in the figure below:
T.MSD309.BA5T
T.MSD309.BA5T can be used in TVs:
DNS V40D8200 (Panel LSC400HV02-W05), DNS V32D2500 (Panel TY315LK12-ACW1 V315H3-CPE6), DNS S32DSB1 (Panel T315HB01 V.1), DNS S39DSB1 (Panel V390HJ1-LE1).
Main features of the DNS S32DSB1 device:
Installed matrix (LED panel) T315HB01 V.1.
Matrix control uses the T460HW03 Timing Controller (T-CON).
The LED driver T315HW07 is used to power the backlight LEDs, it is controlled by the PWM controller MAX16814.
The formation of the necessary supply voltages for all nodes of the DNS S32DSB1 TV is carried out by the MD-F075-0322 power module, or its analogs.
MainBoard - the main board (motherboard) is a T.MSD309.BA5T module, using CPU chips: MSD309BT, SPI Flash: 25Q32FVS1G, W631GG6KB, Audio: TPA3124D2 and others.
DNS TV S32DSB1 with LCD T315HB01, diagonal size 32 "(81 cm) 16: 9. The required brightness of the screen of 400 cd / m2 is provided by LED backlighting. Dynamic contrast ratio of 5000: 1 is achieved by special control of the LED operation depending on the illumination This model uses a panel with edge-mounted backlight LEDs - Edge LED.
There is support for 3D images using passive polarization technology.
The T315HB01 V.1 matrix and the MainBoard T.MSD309.BA5T software provide viewing of broadcasts and movies in high quality HD at a resolution of 1920x1080 pixels in graphics resolution at 1080p (Full HD).
S32DSB1 has built-in SMART software and pre-installed Android operating system. Internet connection can be made via Wi-Fi wireless connection. 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, 1080p. Supported media file formats: MP3, WMA, MPEG4, MKV, JPEG.
Speaker power 20 W (2x10 W) is provided by two speakers. The NICAM STEREO audio processing system is used.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, audio x2, component, SCART, VGA, HDMI x4, USB x3, Ethernet (RJ-45), Wi-Fi. A headphone output is provided. To connect a computer or laptop to this TV model, use the VGA (D-Sub 15) connector on the TV case, this interface supports resolutions: 640x480, 800x600, 1360x768, 1920x1080. The digital tuner is capable of receiving television channels in DVB-T, DVB-C, DVB-T2 standards.
The TV uses the MD-F075-0322 AC adapter.
Dimensions: With stand 755x510x180 mm, Without stand 755x460x85 mm.
TV weight: 10 kg.
Attention! Panel T315HB01 V.1 LED TV DNS S32DSB1 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.