Friday, 21 August 2020

REPAIRING / SERVICING TV DNS C46DC2000

Technical description and composition of the DNS C46DC2000 TV, panel type and modules used. The composition of the modules.
DNS LED
Model: C46DC2000
Chassis / Version: LS1B
Panel: M460F13-E1-S
LED driver (backlight): integrated into PSU
Power Supply (PSU): XR7.820.238V1 R-HS155D-1MF21 R-HS165D-1MF21
MainBoard: JUG7.820.00084054 LS1B 32C2000
IC MainBoard: Spi Flash: 25Q64BSIG, Ram: SK Hunix H5TQ1G63EFR, Audio: TPA31100D2
Tuner: DT21WN-2A-E
Specifications C46DC2000
DNS C46DC2000
General recommendations for TV LCD LED repair
Possible malfunctions
- DNS C46DC2000 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.
With similar manifestations, in some cases, the XR7.820.238V1 power supply module is faulty. 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 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 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 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 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 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 JUG7.820.00084054 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). Sometimes it is necessary to check or replace (if necessary) elements of the MainBoard - Spi Flash: 25Q64BSIG, Ram: SK Hunix H5TQ1G63EFR, Audio: TPA31100D2. In cases where a BGA processor is used, its malfunction is usually detected by a local warm-up method.
If there is no reception of TV channels, but the TV is working properly from external devices, first of all, you need to check the supply voltage of the DT21WN-2A-E tuner and update the software. I2C communication pulses must be monitored with an oscilloscope.
Remember! Attempts to self-repair the DNS C46DC2000 TV, 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!


DOWNLOAD FIRMWARE FOR SPI FLASH  ----------->   DNS C46DC2000 LS1B, Main: JUG7.820.00084054 LS1B 32C2000, Panel: M460F13-E1-S



 The appearance of the MainBoard JUG7.820.00084054 is shown in the figure below:
JUG7.820.00084054
JUG7.820.00084054 can be used in TVs:
BBK 32LEM-1002/T2C (Panel ECG320AB-LDV HD), DNS C46DC2000 (Panel M460F13-E1-S), ERISSON 32LEC2000 (Panel M320X13-E1-H).
External view of the power supply
Main features of the DNS C46DC2000 device:
Installed matrix (LED panel) M460F13-E1-S.
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 C46DC2000 TV is carried out by the XR7.820.238V1 power module, or its analogs.
MainBoard - the main board (motherboard) is a JUG7.820.00084054 module using Spi Flash chips: 25Q64BSIG, Ram: SK Hunix H5TQ1G63EFR, Audio: TPA31100D2 and others.
The DT21WN-2A-E tuner provides reception of television programs and tuning to channels.
DNS TV C46DC2000 with LCD M460F13-E1-S, 46 "(117 cm) diagonal 16: 9. The required brightness of the screen 360 cd / m2 is provided by LED backlighting. Dynamic contrast ratio of 100,000: 1 is achieved by special control of the LEDs depending on the illumination of the areas in the scene The LCD panel uses direct pixel illumination with rear-mounted LEDs - Direct LED.
The M460F13-E1-S matrix and the MainBoard JUG7.820.00084054 software provide viewing of broadcasts and movies in high quality HD at a resolution of 1920x1080 pixels in graphics decomposition at 1080p (Full HD). 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, MPEG4, 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, VGA, HDMI x3, USB. 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, 1280x1024, 1360x768, 1920x1080. The digital tuner is capable of receiving television channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
The TV uses the XR7.820.238V1 power supply.
Dimensions: With stand 1057x662x210 mm, Without stand 1057x620x85 mm.
TV weight: 15 kg.
Attention! The M460F13-E1-S panel of the DNS C46DC2000 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.