Technical description and composition of the DNS E24D20 TV, panel type and modules used. The composition of the modules.DNS LED
Model: E24D20
Chassis / Version: T.MSD309.B63B
Panel: CX236LEDM / M236H1-P08
T-CON: M236H1-P08
LED driver (backlight): integrated into PSU
PWM LED driver: BIT3251
Power Supply (PSU): MP113TH-50
PWM Power: LD7536 (PWM SOT23-6)
MainBoard: T.MSD309.B63B
IC MainBoard: 25Q32BSIG
E24D20 Specifications
DNS E24D20
General recommendations for TV LCD LED repair
Possible manifestations of malfunctions
- DNS E24D20 does not turn on and does not show any signs of operability. Does not blink indicators and does not respond to any control buttons.
In such cases, the MP113-TH50 power supply usually fails. 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 the PWM OB2273 (PWM SOT23-6). It is checked only by replacing it with a known good one.
- 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.
In such cases, the most likely malfunction of the LED panel backlighting elements. 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.
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 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.B63B 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). Complicated MB (SSB) repair is possible only in the conditions of a service center with the necessary equipment. Checking or replacing 25Q32BSIG elements requires the necessary training and professional skills to repair modules at the component level. Problems associated with the use of BGA soldering technologies can sometimes be diagnosed by the warm-up method.
If the TV operates normally from external devices but does not tune to TV channels, the Tuner may be faulty. In such cases, first of all, you should make sure that there are supply voltages at its corresponding terminals. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus. Sometimes the reason for the inoperability of the tuner may be a software failure.
Remember! Attempts to repair the DNS E24D20 TV yourself, 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!
Additional MainBoard RepairThe appearance of the MainBoard T.MSD309.B63B is shown in the figure below:
T.MSD309.B63B
Main features of the DNS E24D20:
Installed matrix (LED panel) CX236LEDM / M236H1-P08.
Matrix control uses Timing Controller (T-CON) M236H1-P08.
To power the backlight LEDs, a converter combined with a power supply is used, controlled by a BIT3251 PWM controller.
The formation of the necessary supply voltages for all nodes of the DNS E24D20 TV is carried out by the MP113TH-50 power module, or its analogs using LD7536 microcircuits (PWM SOT23-6).
MainBoard - the main board (motherboard) is a T.MSD309.B63B module, using 25Q32BSIG chips and others.
DNS E24D20 TV with LCD CX236LEDM, diagonal 24 "(61 cm) in 16: 9 format. The required screen brightness of 250 cd / m² is provided by LED backlighting. Contrast - the ratio of maximum to minimum brightness is 1000: 1. the model uses a panel with an edge arrangement of backlight LEDs - Edge LED.
The CX236LEDM / M236H1-P08 sensor and the MainBoard T.MSD309.B63B 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 480i, 480p, 576i, 576p, 720p, 1080i standards. Supported media file formats: MP3, WMA, MPEG4, DivX, MKV, JPEG.
Speaker power 10 W (2x5 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, SCART, VGA, HDMI, 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, 1280x1024, 1360x768, 1920x1080. The digital tuner is capable of receiving TV channels in DVB-C standards.
The power consumed by the TV operating in mains mode is 48 W. MP113TH-50 power supply.
Dimensions: With stand 580x407x175 mm, Without stand 580x376x38 mm.
TV weight: 4.5 kg.
Attention! Panel CX236LEDM / M236H1-P08 LED-TV DNS E24D20 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.