Thursday, 27 August 2020

REPAIRING / SERVICING TV DNS S29DB1

Technical description and composition of the DNS S29DB1 TV, panel type and modules used. The composition of the modules.
DNS LED
Model: S29DB1
Chassis / Version: T.MSD309
Panel: V290BJ1-LE1
LED backlight: V290B1-LE1-TLEM5
T-CON: V290BJ1-XC01; CM1801B, CM501, CM601, P2003EV6, GT4128
LED driver (backlight): integrated into PSU; 150V
Power Supply (PSU): ER966H Ver1.0
MainBoard: T.MSD309.BA3T
IC MainBoard: CPU: MSD309BT, SPI Flash: 25Q32, DRAM: W631GG6KB-12, HDMI: IT6633E-PKB, Audio: TPA3124D2, DVB-T2: MSB1231-LF
Specifications S29DB1
DNS S29DB1
General recommendations for TV LCD LED repair
Possible manifestations of defects
- DNS S29DB1 does not turn on at all and does not show any signs of operability. Does not blink indicators and does not respond to control buttons.
Most likely in this case, the main switching power supply (SMPS) ER966H is faulty. It is necessary to measure the secondary output supply voltages, and if they are absent, check the serviceability of the power switches of the converters and rectifier diodes for a short circuit.
In case of breakdowns in the secondary circuits, the converter can operate in short-circuit mode, and in case of short-circuit in the elements of the primary circuit, the mains fuse usually breaks off.
Mos-Fet keys used in switching power supplies usually fail due to a malfunction of other elements, which can disable it in key mode, or provoke an excess of the maximum current or voltage values. These can be supply, damper circuits, or elements of OOS (negative feedback) stabilization. The reason for the breakdown of the power switch can also be PWM. It is checked only by replacing it with a known good one.
- There is no image, there is sound, it reacts to the remote control. Or the image may appear for a second when turned on and disappear immediately.
Often, in such cases, there is no backlighting of the LED panel. The reason may 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 should be remembered that it is not possible to determine an open circuit in the LED lines without disassembling the panels using a tester or multimeter without an additional device, for example, a current source. To open all PN junctions connected in series at once, a voltage of several tens of volts may be required. Then you need to open the panel and check each LED separately with a multimeter. If the capabilities of your multimeter do not allow opening the LED in the forward direction or dual LEds are used, then the PN transition of the emergency zener diode can indirectly serve as an indicator of serviceability. In the event of a malfunction of the LED-a, the PN-junction of the zener diode will either be cut off or broken into the K / Z.
- The indicator blinks or is on constantly, the TV does not turn on, 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). Often the MB (SSB) board must be replaced in case of complex malfunctions that are difficult to detect. When trying to repair it, you should check its elements - CPU: MSD309BT, SPI Flash: 25Q32, DRAM: W631GG6KB-12, HDMI: IT6633E-PKB, Audio: TPA3124D2, DVB-T2: MSB1231-LF and replace the failed chips with new ones. Some malfunctions may be associated with the use of BGA soldering technologies in modern Main Board. Typically, such defects are detected by local heating of the chip.
Attention to users! Self-repair of the DNS S29DB1 TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability!

DOWNLOAD FIRMWARE FOR SPI FLASH  ----------->   DNS S29DB1, Main: T.MSD309.BA3T, Panel: V290BJ1-LE1




  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 S29DB1 device:
Installed matrix (LED-panel) V290BJ1-LE1.
Matrix control uses Timing Controller (T-CON) V290BJ1-XC01 ;.
A converter combined with a power supply is used to power the backlight LEDs.
The formation of the necessary supply voltages for all nodes of the DNS S29DB1 TV is carried out by the ER966H power module, or its analogues.
MainBoard - the main board (motherboard) is a T.MSD309.BA3T module, using CPU chips: MSD309BT, SPI Flash: 25Q32, DRAM: W631GG6KB-12, HDMI: IT6633E-PKB, Audio: TPA3124D2, DVB-T2: MSB1231 -LF and others.
Additional technical information about the panel:
Brand: CHIMEI INNOLUX
Model: V290BJ1-LE1
Type: a-Si TFT-LCD, Panel
Diagonal size: 29.0 inch
Resolution: 1366x768, WXGA
Display Mode: Super MVA, Normally Black, Transmissive
Active Area: 631.092x354.816 mm
Surface: Antiglare (Haze 3.5%)
Brightness: 300 cd / m²
Contrast Ratio: 3000: 1
Display Colors: 16.7M (8-bit), CIE1931 72%
Response Time: 9.5 (G to G)
Frequency: 60Hz
Lamp Type: WLED Without Driver
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V
DNS TV S29DB1 with LCD V290BJ1-LE1, diagonal size 29 "(74 cm) 16: 9 format. Necessary screen brightness of 300 cd / m² is provided by LED backlight. Contrast - ratio of maximum brightness to minimum brightness is 4000: 1. This model uses a panel with an edge LED backlight - Edge LED.
The V290BJ1-LE1 sensor and the MainBoard T.MSD309.BA3T software provide HD quality viewing at 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 480i, 480p, 576i, 576p, 720p standards. Supported media file formats: MP3, MPEG4, DivX, MKV, JPEG.
Speaker power 20 W (2x10 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, audio x2, component, SCART, 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 power consumed by the TV operating in mains mode is 65 W. ER966H power supply.
Dimensions: With stand 665x450x180 mm, Without stand 665x402x80 mm.
TV weight: 7.6 kg.
Attention! The V290BJ1-LE1 panel of the DNS S29DB1 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.