Technical description and composition of the LG DM2350D TV, panel type and applicable modules. The composition of the modules.LG LED
Model: DM2350D DM2350DM
Chassis / Version: LD93I
Panel: LM230WF8 (TL) (A2)
LED backlight: 4 strings
LED driver (backlight): EAX63282604 (0)
PWM LED driver: MAX16814B
MOSFET LED driver: 18T10GH TO-252
Power Supply (PSU): Adapter 19V
MainBoard: EAX63977002 (1)
IC MainBoard: CPU: LGE3369B, SPI Flash: MX25L8005, AUDIO: NTP-7050
Tuner: TDSN-G001D
Technical Specifications DM2350D
LG DM2350D
General repair guidelines for TV LCD LED
Possible malfunctions
- The LG DM2350D TV does not turn on and does not show any signs of turning on, does not respond to the control buttons or to the remote control.
In such cases, the fault should be sought first in the Adapter power module.
This TV model is equipped with an external power adapter type Adapter 19V, which the owner can purchase independently, and repairing it may not always be advisable, however, sometimes there is a certain sense to open it and eliminate simple typical defects typical of IPS. Then we recommend that you measure its output voltages and, if they are absent, you should check the health of the power switches and rectifier diodes of the converters for a probable short circuit.
In case of breakdowns of diodes in the secondary circuits, the converter can operate in emergency short circuit mode without output voltages, and during short circuit in the power elements of the primary circuit, the mains fuse and / or current sensor at the source of the key usually breaks.
Breakdown of power switches (MosFet) in pulsed sources is sometimes caused by malfunctions of other circuit elements, for example, in circuits supplying a PWM controller, frequency-setting or damper ones, as well as in negative feedback (OOS) stabilization circuits. PWM controllers (PWM), if they do not have visible damage to the case and open short circuit between the terminals, are usually checked by replacement.
- There is no image, but there is sound, it reacts to the remote control. Or the image appears when you turn it on and immediately disappears
In such cases, the most likely malfunction of the LED backlight elements. The reason can 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.
It is impossible to check the LED line for breaks without disassembling the panel with a multimeter or tester. For these purposes, it is necessary to open all series-connected PN junctions and a voltage of the order of tens of volts will be required, and ideally, a current source. Having disassembled the panel, it is necessary to check each LED separately. Chinese multimeters, as a rule, light up a single 3-volt LED in the forward direction. In the case of using dual 6-volt LEDs, the PN junction of its protective zener diode can serve as a health indicator. In faulty LEDs, the zener diode will either be cut off or broken into short-circuit.
- The TV does not turn on, the indicator indicates standby or operating mode, or blinks.
Repair or diagnostics of the EAX63977002 motherboard should begin by checking the stabilizers and power converters needed to power the chips and matrix. If necessary, update or replace the software (software). In cases of complex repairs of MB (SSB) and with the necessary skills and equipment, sometimes it may be necessary to replace its CPU chips: LGE3369B, SPI Flash: MX25L8005, AUDIO: NTP-7050 and other possible faulty components. Malfunctions associated with the application of BGA soldering technologies are usually easily diagnosed by the heating method.
If the TV works normally from external devices, but does not tune into television channels, the TDSN-G001D tuner may be malfunctioning. In such cases, first of all, you should make sure that there are supply voltages at its corresponding conclusions. It is also necessary to make sure that the tuner and processor can exchange data via the I2C bus. Sometimes the cause of the inoperability of the tuner may be a software failure.
Owners and users of the LG DM2350D TV should remember that self-repair without special knowledge, skills and qualifications can be fraught with negative consequences that can lead to complete non-repairability of the device!
SCHEMATIC diagram ----------------> LG DM2350D Chassis LD93I
To reduce the backlight current in LED drivers with a PWM controller MAX16814 (TSSOP20 MAX16814B), it is necessary to proportionally increase the total resistance of the resistors from terminal 10 (SETI) to the housing. The maximum current in each of the four channels (in milliamps) for the resistance Rseti (in kilo-ohms) is determined from the ratio 1500 / Rset.
The appearance of the MainBoard EAX63977002 is shown in the figure below:EAX63977002
Main features of the device LG DM2350D:
The matrix (LED panel) LM230WF8 (TL) (A2) is installed.
The EAX63282604 LED driver is used to power the backlight LEDs, it is controlled by the MAX16814B PWM controller. As the power elements of the LED driver, keys of the type 18T10GH TO-252 are used.
To power all the internal components of the LG DM2350D TV, an external adapter 19V type source is used.
MainBoard - the main board (motherboard) is an EAX63977002 module, using CPU chips: LGE3369B, SPI Flash: MX25L8005, AUDIO: NTP-7050 and others.
The TDSN-G001D tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: LG Display
Model: LM230WF8-TLA2
Type: a-Si TFT-LCD, Panel
Diagonal size: 23.0 inch
Resolution: 1920x1080, FHD
Display Mode: TN, Normally White, Transmissive
Active Area: 509.184x286.416 mm
Surface: Antiglare
Brightness: 250 cd / m²
Contrast Ratio: 1000: 1
Display Colors: 16.7M (6-bit + Hi-FRC), CIE1931 72%
Response Time: 1.3 / 3.7 (Tr / Td)
Frequency: 60Hz
Lamp Type: 4 strings WLED Without Driver
Signal Interface: LVDS (2 ch, 8-bit), 30 pins
Voltage: 5.0V
