Technical description and composition of the LG 42LM660S TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 42LM660S 42LM660S-ZA.BRUWLJU
Chassis / Version: LD22E (LD22 * / LC22 *)
Panel: LC420EUG (PE) (F1)
LED backlight: 6922L-0023A, 6916L0948A L-Type 6920L-0001C, 6916L0947A R-Type 6920L-0001C
LED driver (backlight): integrated into PSU
PWM LED driver: UC2843BD1 (Step-Up LED), AAT2430AISX, R5F100BCAFP
MOSFET LED driver: STF19NF20, PHT4NQ10LT
Power Supply (PSU): EAX64744201 (1.3) LGP4247L-12LPB-3P EAY62608902
PWM Power: L6599AD, FAN7930BG (PFC), STR-A6059H (Stby)
MOSFET Power: STF13NM60N, STF10NM60N
MainBoard: EAX64307906 (1.0) EBR75226821
IC MainBoard: LCE2112, H5TQ2G63DFR, KLM2G1HE3F, MICOM R5F100GEA, TPS65178, STA3808WE, 24C16
Tuner: TDSN-G351D
Control: Remote: AKB73615303
Specifications 42LM660S
LG 42LM660S
General repair guidelines for TV LCD LED
Possible manifestations of defects
- LG 42LM660S TV does not turn on, does not respond to the remote control and control panel buttons, indicators do not light up and do not blink.
With such manifestations, a malfunction is most likely to be detected in the EAX64744201 power module. It is necessary to measure its output voltages, and in case of their absence (full or partial), it is necessary to check the serviceability of power switches (STF13NM60N, STF10NM60N) of converters and rectifier diodes for the presence of a possible short circuit.
In case of any breakdowns in the secondary circuits, the converter can operate in emergency short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse or the current sensor at the source of the key more often 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 L6599AD, FAN7930BG (PFC), STR-A6059H (Stby), 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 commands from the remote control. Or the image appears immediately after turning on and disappears.
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.
It should be remembered that it is not possible to determine the break 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 it is necessary to open the panel and check each LED separately with a multimeter. If the capabilities of your multimeter do not allow you to open the LED in the forward direction or dual LEd are used, then the PN junction of the emergency zener diode can indirectly serve as a health indicator. In case of LED-a failure, the zener diode PN junction will either be cut off or broken into short-circuit.
- The indicator blinks or lights constantly, the TV does not turn on, does not respond to the remote control.
Repair or diagnostics of the EAX64307906 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). Sophisticated MB board repair (SSB) is in some cases possible and practiced by repairmen. To do this, check and, if necessary, replace the elements LCE2112, H5TQ2G63DFR, KLM2G1HE3F, MICOM R5F100GEA, TPS65178, STA3808WE, 24C16. BGA chip malfunctions are usually easy to detect by warming up.
Before changing the TDSN-G351D tuner, if it is not possible to tune to television channels, make sure that there are supply voltages that must be measured at the corresponding tuner pins and check the software for correctness. The pulses of the data exchange of the tuner with the processor can be controlled by an oscilloscope
It should be remembered! Attempts to self-repair the LG 42LM660S TV, 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!
To reduce the backlight current in LED drivers with the AAT2430AISX controller, increase the resistance of the resistor from terminal 50 (ISET) to the housing, for example, from 3 KOhm to 4.7 KOhm. Currents will proportionally decrease in each of the 16 channels. With a parallel connection of channels, currents are summed.
SCHEMATIC DIAGRAM ----------> LG CHASSIS LD22E; MODEL 42LM660S, 42LM660T, 42LM669S, 42LM669T, 42LM660S/660T-ZA 42LM669S/669T-ZC
The appearance of the MainBoard EAX64307906 is shown in the figure below:EAX64307906
EAX64307906 can be used in TVs:
LG 32LM640T ZA (Panel LC320EUA PE F2), LG 32LS570T (Panel LC320EUN (SE)(M2)), LG 47LM620S (Panel LC470EUE (SE)(F4)), LG 42LM670T (Panel LC420EUG(PE)(F2)), LG 42LM640T 42LM640S (Panel LC420EUG (PE)(F1)), LG 42LM620T (Panel LC420EUE (SE)(F1)), LG 47LM660T (Panel LC470EUG (PE)(F1)), LG 42LS570T (Panel T420HVN01.0), LG 42LS570S ZB (Panel LC420EUE (SE)(M1)), LG 42LM669T (Panel LC420EUG (PE)(F2)), LG 42LM669S (Panel LC420EUG (PE)(F1)), LG 37LM620T (Panel LC370EUN (SE)(F2)), LG 47LM669 (Panel LC470EUG (PE)(F2)), LG 32LS570S ZB (Panel LC320EUN (SE)(M2)), LG 47LM620T (Panel LC470EUE (SE)(F3)), LG 47LM761T ZA (Panel LC470EUH (PE)(F1), LG 32LM620S (Panel LC320EUN (SE)(F2) ), LG 47LM670T 47LM670T-ZA.BRUWLJU (Panel LC470EUG (PE)(F1)), LG 42LM660S 42LM660S-ZA.BRUWLJU (Panel LC420EUG (PE)(F1)), LG 42LM660T 42LM660T-ZA.BRUWLJU (Panel LC420EUG (PE)(F1) ), LG 32LM620T (Panel LC320EUN (SE)(F3)), LG 55LM620T 55LM620T-ZE (Panel LC550EUE (SE)(F1)).
The appearance of the power supply
Main features of the device LG 42LM660S:
Installed matrix (LED-panel) LC420EUG (PE) (F1).
To power the backlight LEDs, a converter is used, combined with a power supply unit, controlled by a PWM controller UC2843BD1 (Step-Up LED), AAT2430AISX, R5F100BCAFP. As the power elements of the LED driver, keys of the STF19NF20, PHT4NQ10LT type are used.
The necessary supply voltages for all nodes of the LG 42LM660S TV are generated by the EAX64744201 power supply module or its analogs using L6599AD, FAN7930BG (PFC), STR-A6059H (Stby) microcircuits and power switches of the STF13NM60N, STF10NM60N type.
MainBoard - the main board (motherboard) is an EAX64307906 module, using microcircuits LCE2112, H5TQ2G63DFR, KLM2G1HE3F, MICOM R5F100GEA, TPS65178, STA3808WE, 24C16 and others.
The TDSN-G351D tuner provides television reception and channel tuning.
Additional technical information about the panel:
Brand: LG Display
Model: LC420EUG-PEF1
Type: a-Si TFT-LCD, Panel
Diagonal size: 42 inch
Resolution: 1920x1080, FHD
Display Mode: S-IPS, Normally Black, Transmissive
Active Area: 930.24x523.26 mm
Surface: Antiglare (Haze 1%), Hard coating (2H)
Brightness: 360 cd / m²
Contrast Ratio: 1400: 1
Display Colors: 16.7M (8-bit), CIE1931 68%
Response Time: 8/10 (Tr / Td)
Frequency: 60Hz
Lamp Type: WLED Without Driver
Signal Interface: EPI, 100 pins
Voltage: 12.0V