Technical description and composition of the DNS M24DM8 TV, panel type and modules used. The composition of the modules.DNS LED
Model: M24DM8
Chassis / Version: T.SIS231.T65
Panel: M236HGE-L20 ReV.C1
LED driver (backlight): 12V Led-Driver Out: 46.5V 65mA
Power Supply (PSU): Adapter 12V
MainBoard: T.SIS231.T65
IC MainBoard: SPI Flash: 25Q64BSIG, NT5CB64M16FP, YD1517P
Tuner: SI2T6Q
Specifications M24DM8
DNS M24DM8
General recommendations for TV LCD LED repair
Possible malfunctions
- DNS M24DM8 TV does not turn on, does not respond to the remote control and control panel buttons, does not light up or blink indicators.
Usually with such manifestations, the defect is caused by faulty elements in the main power supply module Adapter.
The owner of the TV can purchase an external power supply of type Adapter on his own and its repair is not always advisable. In any case, the simplest typical defects characteristic of most SMPS circuits can be easily detected and eliminated after opening. Its output voltages should be measured and, in their absence, the serviceability of the power switches and rectifier diodes in the converters should be checked for possible breakdown.
In case of diode breakdowns in the secondary circuits, the converter can operate in an emergency mode of short circuit without output voltages, and in case of a short circuit in the power elements of the primary circuit, the mains fuse and / or the current sensor in the source of the key usually breaks off.
Breakdown of Mos-Fet switches used in switching power supplies is often caused by malfunctions of other elements, for example, in the power supply circuit of a PWM controller, in frequency setting or damper circuits, as well as in negative feedback stabilization. PWM microcircuits (PWM) are usually checked by replacing them with new ones, or knowingly working.
- 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.
Usually, in such cases, a malfunction is detected in the LED panel backlight nodes. The reason for this may be an open circuit in the LED circuit, or a problem in stabilizing their power supply.
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 TV does not turn on, the indicator signals the standby or operating mode, or blinks.
Repair or diagnostics of the T.SIS231.T65 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). Complicated repair of MB (SSB) board is in some cases possible and practiced by repairmen. To do this, check and, if necessary, replace the SPI Flash elements: 25Q64BSIG, NT5CB64M16FP, YD1517P. Malfunctions in BGA chips are usually easy to detect by warm-up.
In cases where there is no tuning for terrestrial or cable TV channels, you should make sure that the software is correct, as well as that the supply voltages on the SI2T6Q tuner outputs match. It is also necessary to check with an oscilloscope the presence of pulses of data exchange between the tuner and the processor via the I2C bus.
Attention to TV owners! Attempts to repair the DNS M24DM8 on your own are not recommended by the manufacturer and can lead to serious negative consequences!
DOWNLOAD FIRMWARE FOR SPI FLASH -----------> DNS M24DM8, Main: T.SIS231.T65, Panel: M236HGE-L20 ReV.C1
The appearance of the MainBoard T.SIS231.T65 is shown in the figure below:T.SIS231.T65
T.SIS231.T65 can be used in TVs:
DNS M24DM8 (Panel M236HGE-L20 ReV.C1), DNS 22AE7000 (Panel CX215LEDM), ERISSON 28LEP91 (Panel st2751a01-1), ROLSEN RL-19E1501T2C (Panel V185BJ1-PE1), RUBIN RB-22SE5FT2C (Panel LM215DA-T01), RUBIN RB-22SE9FT2C (Panel M215HTN01.1), SHIVAKI STV-24LEDGR9 (Panel M236HGE-L20 Rev.C1), SHIVAKI STV-24LEDGW9 (Panel M236H3-LA3), SHIVAKI STV-24LED12 (Panel M236HGE-P01), THOMSON T24E09DU-01B (Panel V236BJ1-P03 (C1)).
Key features of the DNS M24DM8:
Installed matrix (LED panel) M236HGE-L20 ReV.C1.
A 12V LED driver is used to power the backlight LEDs.
To power all internal nodes of the DNS M24DM8 TV, an external adapter 12V is used.
MainBoard - the main board (motherboard) is a T.SIS231.T65 module, using SPI Flash chips: 25Q64BSIG, NT5CB64M16FP, YD1517P and others.
The SI2T6Q tuner provides reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: CHIMEI INNOLUX
Model: M236HGE-L20
Type: a-Si TFT-LCD, Panel
Diagonal size: 23.6 inch
Resolution: 1920x1080, FHD
Display Mode: TN, Normally White, Transmissive
Active Area: 521.28x293.22 mm
Surface: Antiglare (Haze 25%), Hard coating (3H)
Brightness: 300 cd / m²
Contrast Ratio: 1000: 1
Display Colors: 16.7M (8-bit), CIE1931 72%
Response Time: 1.5 / 3.5 (Tr / Td)
Frequency: 60Hz
Lamp Type: 4 strings WLED Without Driver
Signal Interface: LVDS (2 ch, 8-bit), 30 pins
Voltage: 5.0V
DNS TV M24DM8 with LCD M236HGE-L20, diagonal size 24 "(61 cm) 16: 9. The required brightness of the screen of 250 cd / m² is provided by LED backlighting. Contrast - the ratio of maximum to minimum brightness is 1500: 1. This model uses a panel with backlight LEDs - Edge LED.
The M236HGE-L20 ReV.C1 matrix and the MainBoard T.SIS231.T65 software provide viewing of broadcasts and movies in high quality HD at a resolution of 1920x1080 pixels in graphics resolution 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.
The power of the sound system of 6 W (2x3 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, component, SCART, RGB, VGA, HDMI, 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, 1360x768, 1920x1080. The digital tuner is capable of receiving television channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
The TV uses an Adapter.
Dimensions: With stand 569x397x140 mm, Without stand 569x352x50 mm.
TV weight: 3.9 kg.
Attention! Panel M236HGE-L20 ReV.C1 DNS LED TV M24DM8 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.