Technical description and composition of the LG 22LF450U TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 22LF450U
Chassis / Version: LD41A
Panel: V236BJ1-LE2
LED backlight: EDGE LED
LED driver (backlight): integrated into MainBoard
PWM LED driver: DT1641AS (TPS40210)
MOSFET LED driver: AOD478
Power Supply (PSU): Adapter
MainBoard: EAX65377508 (1.0)
IC MainBoard: CPU: LGE2134, Eeprom: 24C256 SPI Flash: MX25L8005, Nand: H27U1G8F, Audio: TAS5733
Tuner: EBL61400501 TDJM-G101D
Technical Specifications 22LF450U
LG 22LF450U
General repair guidelines for TV LCD LED
Possible malfunctions
- The LG 22LF450U TV does not turn on, does not respond to the remote control and buttons on the control panel, does not light up or blink indicators.
In some of these cases, the main switching power supply, the Adapter module, is faulty.
The owner of the TV can purchase an external power supply unit such as Adapter and repairing it is not always advisable. In any case, the simplest typical defects characteristic of most IIP schemes can be easily detected and eliminated after opening. It is necessary to measure the output voltages in its secondary circuits, and if they are completely absent, it is necessary to check the serviceability of power switches and rectifier diodes for possible breakdown (short circuit).
In case of diode breakdowns 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.
Mos-Fet power switches, used in switching power supplies, sometimes fail due to a malfunction of any other elements that can put it out of operation in key mode or create an excess of the maximum permissible parameters of the switch. These can be elements supplying the PWM controller, frequency-setting or damping circuits, or negative feedback elements in the stabilization circuit. PWM controllers, in the absence of visible damage or frank short-circuit between the terminals, are checked by replacing with new, or obviously working.
- There is no image, 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 backlight nodes of the LED panel. 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.
To check the LED lines for breaks without disassembling the panel, for example, a current source will help. It is impossible to open series-connected PN junctions with a simple multimeter, a voltage of the order of several tens of volts is required.
- The TV does not turn on, the indicator indicates standby or operating mode, or blinks.
Repair or diagnostics of the EAX65377508 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: LGE2134, Eeprom: 24C256 SPI Flash: MX25L8005, Nand - H27U1G8F Sound-TAS5733 and other possible faulty components. Malfunctions associated with the application of BGA soldering technologies are usually easily diagnosed by the heating method.
The malfunction of the tuner EBL61400501 is established after checking the software and all the supply voltages at its terminals. The data exchange of the tuner with the processor via the I2C bus can be controlled by an oscilloscope.
Once again, we remind TV users: you should not make attempts to repair it yourself without the appropriate knowledge, experience and the necessary qualifications! Entrust repair to professionals with sufficient experience in the field of repair of electronic equipment.
FIRMWARE FOR SPI FLASH, EEPROM -------------> LG 22LF450U LD41A, Main: EAX65377508 (1.0), Panel: V236BJ1-LE2.
Service manual and schematic diagram ------------------> LG 22LF450U Chassis LD41A
To reduce the backlight current in LED drivers with a DT1641AS controller (DT1641S), you can increase the total resistance of the resistors from pin 7 (RISET) to the chassis. The exact proportional dependence may not be observed if there is additional control on this input, then the ratings should be selected empirically.
The appearance of the MainBoard EAX65377508 is shown in the figure below:EAX65377508
EAX65377508 can be used in TVs:
LG 24LF450U (Panel V236BJ1-LE2 REV.C1), LG 22LF450U (Panel V236BJ1-LE2).
Main features of the device LG 22LF450U:
Installed matrix (LED-panel) V236BJ1-LE2.
To power the backlight LEDs, a converter is used, combined with the EAX65377508 main board, controlled by the DT1641AS PWM controller (TPS40210). As the power elements of the LED driver, keys of the AOD478 type are used.
To power all the internal components of the LG 22LF450U TV, an external adapter type source is used.
MainBoard - the main board (motherboard) is an EAX65377508 module, using CPU chips: LGE2134, Eeprom: 24C256 SPI Flash: MX25L8005, Nand: H27U1G8F, Audio: TAS5733 and others.
The tuner EBL61400501 TDJM-G101D provides reception of television programs and tuning to channels.
Additional technical information about the panel:
Brand: CHIMEI INNOLUX
Model: V236BJ1-LE2
Type: a-Si TFT-LCD, Panel
Diagonal size: 23.6 inch
Resolution: 1366x768, WXGA
Display Mode: Super MVA, Normally Black, Transmissive
Active Area: 521.471x293.184 mm
Surface: Antiglare (Haze 1%), Hard coating (3H)
Brightness: 250 cd / m²
Contrast Ratio: 3000: 1
Display Colors: 16.7M (8-bit), CIE1931 72%
Response Time: 8.5 (G to G)
Frequency: 60Hz
Lamp Type: WLED Without Driver
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V