Technical description and composition of the LG 22LF491U TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 22LF491U
Chassis / Version: LD46S LE46S
Panel: HC215EXN-SLDR3-41XX
LED backlight: EDGE LED
LED driver (backlight): integrated into MainBoard
PWM LED driver: DT1641AS
MOSFET LED driver: AOD478
Power Supply (PSU): Adapter
MainBoard: EAX65588502 (1.0)
IC MainBoard: CPU: LGE2122, EEPROM: 24C256, NAND: H26M31003GMR
Tuner: TDJM-G101D
Technical Specifications 22LF491U
LG 22LF491U
General repair guidelines for TV LCD LED
Possible malfunctions
- The LG 22LF491U TV does not turn on at all. The control lights do not light or flash. The TV on the remote control and the control panel buttons do not respond.
In some of these cases, a malfunction is detected in the adapter power module.
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 its output voltages and, if they are absent, to check for short-circuit probabilities in the converters, power switches and rectifier diodes.
In case of breakdowns of semiconductors in the secondary circuits of any converter, as a rule, it can operate in emergency short-circuit mode without output voltages, and during short circuit in the elements of the primary circuit, the main fuse and, less often, the current sensor at the source of the key are most often cut off.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, in the power supply circuit of a PWM controller, in frequency-setting or damping circuits, as well as in Negative Stabilization Feedback. PWM microcircuits are usually checked by replacement with new ones, or obviously working.
- There is no image, there is sound, it responds to the remote control. Or the image may appear for a second when turned on and immediately disappears.
As a rule, in such cases there is no display backlight. 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 indicator on the front panel blinks, the TV does not turn on in operating mode, it does not respond to the remote control.
Repair or diagnostics of the EAX65588502 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).
TV users and owners need to remember that attempts to self-repair a LG 22LF491U TV without the appropriate qualifications and necessary experience can lead to serious negative consequences!
FIRMWARE FOR EEPROM -----> LG 22LF491U LD46S LE46S, Main: EAX65588502 (1.0), Panel: HC215EXN-SLDR3-41XX.
Service manual and schematic diagram ----------------------> LG 22LF491U Chassis LD46W
The appearance of the MainBoard EAX65588502 is shown in the figure below:EAX65588502
Main features of the device LG 22LF491U:
Installed matrix (LED-panel) HC215EXN-SLDR3-41XX.
To power the backlight LEDs, a converter is used, combined with the EAX65588502 main board, controlled by the DT1641AS PWM controller. As the power elements of the LED driver, keys of the AOD478 type are used.
To power all the internal components of the LG 22LF491U TV, an external adapter type source is used.
MainBoard - the main board (motherboard) is an EAX65588502 module using CPU chips: LGE2122, EEPROM: 24C256, NAND: H26M31003GMR and others.
The TDJM-G101D tuner provides television reception and channel tuning.