Monday, 24 August 2020

REPAIRING / SERVICING TV DNS K32A619

Technical description and composition of the DNS K32A619 TV, panel type and modules used. The composition of the modules.
DNS LED
Model: K32A619
Chassis / Version: KL32GT618
Panel: LC320DXE (SF) (R1)
T-CON: 6870C-0442B FAHL7V 320 3C3; TPS65175, TL2357ML, 404RP
LED driver (backlight): integrated into MainBoard
PWM LED driver: OCP8121
Power Supply (PSU): integrated into MainBoard
PWM Power: FAN6755
MainBoard: KL32GT618-LCD-196YTK KB-6150
IC MainBoard: IT6633E-P, NXP18273, 25Q32BVS5G, STA333W, RF9886, ME94358
Tuner: Tuner
Control: 210-000510 / 1
Specifications K32A619
DNS K32A619
General recommendations for TV LCD LED repair
Possible manifestations of defects
- K32A619 DNS TV does not turn on. There are no signs of operability. The indicators on the front panel do not light or flash, and does not respond to the remote control and control buttons.
In such cases, the power supply is often faulty - the AC / DC converter of the mains voltage, which is combined with the elements of the main board KL32GT618-LCD-196YTK. It is necessary to make sure that there are secondary voltages and, if they are absent, check the power switches and rectifier diodes for a short circuit.
In the event of breakdowns in the secondary circuits, the converter can operate in a short-circuit mode, and in the event of a short circuit in the power elements of the primary circuit, the mains fuse is usually cut off.
Breakdown of Mos-Fet keys used in switching power supplies is often caused by malfunctions of other elements, for example, supply, frequency setting, damper ... as well as elements of Negative Feedback Stabilization. The PWM microcircuit (PWM) FAN6755 can also cause a malfunction of the power switch of the converter and is checked by replacement.
- 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.
As a rule, in such cases there is no display backlight. The reason for this may be an open circuit in the LED circuit, or a problem in stabilizing their power supply.
To identify an open circuit in the LED lines without disassembling the panel, a current source is required. It is impossible to open the junctions connected in series with a simple multimeter; a voltage of several tens of volts is required.
- The TV does not turn on, the indicator signals the standby or operating mode, or blinks.
Repair or diagnostics of the KL32GT618-LCD-196YTK 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). In some cases, to repair the MB (SSB) board, it may be necessary to replace chips - IT6633E-P, NXP18273, 25Q32BVS5G, STA333W, RF9886, ME94358 with new or known good ones. In cases where BGA technologies are used, defects are usually localized by heating.
Before replacing the Tuner, if there is no tuning to the channels, you must first check the software and the supply voltage at its outputs. You also need to make sure that the tuner and processor can exchange data via the I2C bus
Owners of the K32A619 TV are advised to contact only qualified specialists with the necessary experience for repair! Attempts to repair yourself without the appropriate knowledge and skills can lead to irreversible negative consequences!
One of the typical DNS K32A619 faults often occurs in the LED panel LC320DXE (SF) (R1) from LG.
External manifestations: no image, display backlight does not work. In most such cases, the LEDs are faulty, which, when checked, turn out to be either open-circuit or with punctured internal zener diodes.
The LEDs need to be replaced, and the maximum current from the driver is limited to 10-20%.


DOWNLOAD FIRMWARE FOR SPI FLASH  ----------->   DNS K32A619, Main: KL32GT618-LCD-196YTK KB-6150, Panel: LC320DXE (SF)(R1)


 The appearance of the MainBoard KL32GT618-LCD-196YTK is shown in the figure below:
KL32GT618-LCD-196YTK
Main features of DNS K32A619 device:
Installed matrix (LED panel) LC320DXE (SF) (R1).
Matrix control uses the Timing Controller (T-CON) 6870C-0442B.
To power the backlight LEDs, a converter combined with the main board KL32GT618-LCD-196YTK is used, controlled by the OCP8121 PWM controller.
The power module is combined with the MainBoard and is made according to the AC / DC flyback converter circuit using FAN6755 microcircuits.
MainBoard - the main board (motherboard) is a KL32GT618-LCD-196YTK module, using the IT6633E-P, NXP18273, 25Q32BVS5G, STA333W, RF9886, ME94358 and others.
Tuner Tuner provides reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: LG Display
Model: LC320DXE-SFR1
Type: a-Si TFT-LCD, Panel
Diagonal size: 31.5 inch
Resolution: 1366x768, WXGA
Display Mode: IPS, Normally Black, Transmissive
Active Area: 697.685x392.256 mm
Surface: Antiglare (Haze 1%), Hard coating (3H)
Brightness: 300 cd / m²
Contrast Ratio: 1200: 1
Display Colors: 16.7M (6-bit + Hi-FRC), CIE1931 68%
Response Time: 6 (G to G)
Frequency: 60Hz
Lamp Type: WLED Without Driver
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V
DNS TV K32A619 with LCD LC320DXE, diagonal size 32 "(81 cm) 16: 9. The required brightness of the screen 380 cd / m2 is provided by LED backlighting. Contrast - the ratio of maximum brightness to minimum is 1200: 1. In LCD -panel uses direct pixel illumination with rear-mounted LEDs - Direct LED.
The LC320DXE (SF) (R1) sensor and MainBoard KL32GT618-LCD-196YTK software provide high quality HD 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 digital signal shaping takes place 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 x3, USB. 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, 1024x768, 1360x768.
The TV uses a power supply unit as part of the MainBoard.
Dimensions: With stand 736x496x180 mm, Without stand 736x443x75 mm.
Attention! The LC320DXE (SF) (R1) panel of the DNS K32A619 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.