Thursday, 27 August 2020

REPAIRING / SERVICING TV DNS S39DSB1

Technical description and composition of the DNS S39DSB1 TV, panel type and modules used. The composition of the modules.
DNS LED
Model: S39DSB1
Chassis / Version: T.MSD309.BA5T
Panel: V390HJ1-LE1
T-CON: 390HJ1-CE1; CM2805A, CM501
LED driver (backlight): L390H1-1EE
PWM LED driver: HAI5208BP, HAI7203HA
MOSFET LED driver: M8014D
Power Supply (PSU): AY080D-4SF 3BS0041014
MainBoard: T.MSD309.BA5T B.AML8726M3.2
IC MainBoard: CPU: MSD309BT, SPI Flash: 25Q32FVS1G, W631GG6KB, Audio: TPA3124D2
Specifications S39DSB1
DNS S39DSB1
General recommendations for TV LCD LED repair
Possible manifestations of defects
- DNS S39DSB1 does not turn on and does not show any signs of operability at all. Does not blink indicators and does not respond to control buttons.
Usually with similar manifestations, the defect is caused by faulty elements in the main power module AY080D-4SF. It is necessary to measure its output supply voltages, and if they are absent, check the serviceability of the power switches of the converters and rectifier diodes for the probability of breakdown in semiconductor PN junctions.
In case of any breakdown of semiconductors in the secondary circuits, the converter can usually operate normally in an 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 in the source of the key.
Mos-Fet power switches used in switching power supplies sometimes fail due to a malfunction of any other elements that can disable it in the key mode, or create an excess of the maximum permissible key parameters. These can be elements supplying a PWM regulator, frequency setting or damper circuits, or elements of negative feedback in the stabilization circuit. PWM controllers, in the absence of visible damage or outright short circuits between the terminals, are checked by replacing them with new ones, or knowingly 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.
Often, in such cases, there is no backlighting of the LED panel. The reason for this may be an open circuit in the LED circuit, or a problem in stabilizing their power supply.
When trying to detect a break in the LED lines, it should be borne in mind that it is difficult to do this without disassembling the panel. For example, a current source is needed to open PN junctions connected in series.
- The TV does not turn on, the indicator signals the standby or operating mode, or blinks.
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). If it is not possible to replace the MB (SSB) board, you need to check the health of its elements - CPU: MSD309BT, SPI Flash: 25Q32FVS1G, W631GG6KB, Audio: TPA3124D2. Defective components must be replaced.
Owners and users of the DNS S39DSB1 TV should remember that self-repair without special knowledge, skills and qualifications can be fraught with negative consequences that can lead to the complete non-repairability of the device!



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

 To reduce the backlight current in LED drivers with a HAI7203HA controller, increase the total resistance of the resistors from pin 12 (ISET) to the case. The currents will decrease proportionally in each of the 8 channels. When the channels are connected in parallel, the currents are summed up.
Additional MainBoard Repair
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 S39DSB1 device:
Installed matrix (LED panel) V390HJ1-LE1.
Matrix control uses Timing Controller (T-CON) 390HJ1-CE1 ;.
The LED driver L390H1-1EE is used to power the backlight LEDs, controlled by the PWM controller HAI5208BP, HAI7203HA. The keys of the M8014D type are used as power elements of the LED driver.
The formation of the necessary supply voltages for all nodes of the DNS S39DSB1 TV is carried out by the AY080D-4SF 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.
Additional technical information about the panel:
Brand: CHIMEI INNOLUX
Model: V390HJ1-LE1
Type: a-Si TFT-LCD, Panel
Diagonal size: 39 inch
Resolution: 1920x1080, FHD
Display Mode: Super MVA, Normally Black, Transmissive
Active Area: 853.92x480.33 mm
Surface: Antiglare (Haze 3.5%), Hard coating (3H)
Brightness: 300 cd / m²
Contrast Ratio: 3500: 1
Display Colors: 16.7M (8-bit), CIE1931 68%
Response Time: 9.5 (G to G)
Frequency: 60Hz
Lamp Type: WLED Embedded (LED Driver)
Signal Interface: LVDS (2 ch, 8-bit), 51 pins
Voltage: 12.0V
DNS TV S39DSB1 with LCD V390HJ1-LE1, diagonal 39 "(99 cm) in 16: 9 format. The required screen brightness of 300 cd / m2 is provided by LED backlighting. Dynamic contrast ratio of 5000: 1 is achieved by special control of LED operation depending on from the illumination of areas in the scene.This model uses a panel with an edge-mounted backlight LEDs - Edge LED.
The V390HJ1-LE1 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 decomposition at 1080p (Full HD).
S39DSB1 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 AY080D-4SF power supply.
Dimensions: With stand 890x587x212 mm, Without stand 890x532x76 mm.
TV weight: 13.6 kg.
Attention! The V390HJ1-LE1 panel of the DNS S39DSB1 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.