Technical description and composition of the LG 37LV370S TV, panel type and applicable modules. The composition of the modules.LG LED
Model: 37LV370S
Chassis / Version: LD12B
Panel: T370HW05 V.1
LED backlight: 73.37T07.001-0-CS1
T-CON: T460HW03 VF CTRL BD AUO-12306 BD8160EFV G582N AUO-G1422
LED driver (backlight): T315HW07 V8 BD 31T14-D06
PWM LED driver: MAX16814, RM5103
MOSFET LED driver: P3506DD, P1825AS
Power Supply (PSU): BD 31T14-D06
PWM Power: FAN7930B (PFC), L6599AD (PWM Resonant)
MainBoard: EAX63557704 (0)
IC MainBoard: CPU: LGE35230, Nand: TC58DVG3S0ETA, DDR: K4B2G1646C,
Tuner: TDFQ-G001D
Control: AKB73275605
Specifications 37LV370S
LG 37LV370S
General repair guidelines for TV LCD LED
Repair of the LG 37LV370S ZB TV should begin with a fault diagnosis, which involves a careful examination of the external and internal elements of the device. Often, based on certain external signs, it may be possible to draw certain conclusions about the reasons for the failure of certain elements of the circuit even before the necessary measurements are made, which will determine the further algorithm for troubleshooting and localizing the defect. If ring cracks are detected in the soldering of the terminals of the elements or dangling connecting tracks, swollen capacitors or charred resistors - all this can be characteristic signs of the causes or consequences of an already known typical malfunction.
In the case when the 37LV370S does not turn on, does not respond to the remote control and buttons on the front panel, does not blink bulbs and does not show any signs of operability, the BD 31T14-D06 power supply module is probably faulty in this case. If it is serviceable with such manifestations, it is necessary to check the power supply stabilizer (converter) of the processor on the motherboard. When repairing the power supply, it is advisable to start the diagnostics by checking the mains fuse and the electrolytic capacitors of the filters of the converter secondary rectifiers. In the event of a fuse breaking, the reason should be sought in the power semiconductor elements of the pulse converter of the main power supply. First of all, it is necessary to check the diodes of the bridge of the rectifier of the mains voltage and the power switch (s) of the converter.
Power switches in pulsed power supplies (SMPS) fail extremely rarely for no reason and, if they are broken, it is necessary to look for a malfunction in the stabilization circuits by checking electrolytic capacitors, semiconductor devices, and resistors in the primary circuit. The reason may be a malfunction of the FAN7930B L6599AD PWM controller chip, which can only be checked by replacing it with a new or obviously working one.
If there is no image when you turn on the LG 37LV370S, or it appears for a second and disappears, but there is sound, most likely there is a malfunction in the backlight LED circuit of the T370HW05 V.1 panel, or in their power converter. It is necessary to check the electrolytic capacitors of the filter of the secondary rectifiers in the general power supply unit.
Often in the absence of backlighting, disassembling the panel is required. It is necessary to check the serviceability of the transitions of the LEDs, as well as the reliability of the contact connections in the lines and connectors.
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.
On the EAX63557704 (0) motherboard, in case of a malfunction, you should first check the performance of all stabilizers or power converters of the microcircuits and, if necessary, update the software (software).
If you suspect a malfunction of the TDFQ-G001D tuner, first of all, make sure that there is a supply voltage on the corresponding output of the tuner.
Attention! For users and owners of 37LV370S TVs who do not have the appropriate qualifications, knowledge and experience, we categorically do not recommend attempting self-repair in order to avoid negative consequences that could lead to complete non-repairability of the device.
schematic diagram -------------> LG CHASSIS : LD12B MODEL : 37LV370S, 37LV370S-ZB, 37LV375G/S/W, 37LV375G/S/W-ZC
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 / Rseti.
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The appearance of the MainBoard EAX63557704 is shown in the figure below:EAX63557704
EAX63557704 can be used in TVs:
LG 37LV370S (Panel T370HW05 V.1), LG 42LV370S (Panel LC420EUN (SD) (V5)), LG 32LV3700 (Panel T315HW07 V.8), LG 42LV3700 (Panel LC420EUN (SD)(V3)), LG 47LV370S ZB (Panel LC470EUE (SD)(V1)), LG 32LV370S (Panel T315HW07 V.8).
PSU Advanced
According to the conditions of compliance with modern world standards for household switching power supplies, the BD module provides for the use of a Power Factor Correction unit. The PFC circuit is a flyback converter based on the FAN7930B PWM controller. The reactance of an electrolytic capacitor of a line filter at a frequency of 50-60 Hz is usually not more than 20-30 ohms and its charge directly from the network through open diodes could reach tens of amperes per pulse if no filtering were applied.
As a result of the PFC conversion, an increased voltage on the capacitor (about 380V) cannot directly open the rectifier diodes, on the anode of which the voltage will always be slightly less (about 300V) and then its charging current will always be limited by the elements of the PWM controller. As a result, the envelope of the high-frequency pulses of the consumed current will repeat the shape and phase of the input sinusoidal voltage. The presence of an increased voltage (+ 380V) on the network capacitor indicates the serviceability of the PFC node.
Main features of the device LG 37LV370S:
Installed matrix (LED-panel) T370HW05 V.1.
The matrix control uses the Timing Controller (T-CON) T460HW03.
The LED driver T315HW07 is used to power the backlight LEDs, it is controlled by the PWM controller MAX16814, RM5103. As power elements of the LED driver, keys of the type P3506DD, P1825AS are used.
The necessary supply voltages for all nodes of the LG 37LV370S TV are generated by the BD power module or its analogs using FAN7930B (PFC), L6599AD (PWM Resonant) microcircuits.
MainBoard - the main board (motherboard) is an EAX63557704 module, using CPU chips: LGE35230, Nand: TC58DVG3S0ETA, DDR: K4B2G1646C, and others.
The TDFQ-G001D tuner provides television reception and channel tuning.
Information from an alternative source:
LG 37LV370S-ZB Chassis LD12B
Panel Type (Matrix): T370HW05 V.1
Motherboard: EAX63557704 (0), Tuner: TDFQ-G001D
T-con: T460HW03 VF CTRL BD, AUO-12306, BD8160EFV, G582N, AUO-G1422, LED driver: T315HW07 V8 LED Driver BD 31T14-D06, MAX16814, G1564,
PSU: EAX62865601 / 8, FAN7930B, L6599AD
Remote control: AKB73275605
Additional technical information about the panel:
Brand: AUO
Model: T370HW05 V1
Type: a-Si TFT-LCD, Panel
Diagonal size: 37 inch
Resolution: 1920x1080, FHD
Display Mode: AMVA3, Normally Black, Transmissive
Active Area: 819.36x460.89 mm
Surface: Antiglare (Haze 2%), Hard coating (3H)
Brightness: 360 cd / m²
Contrast Ratio: 3600: 1
Display Colors: 16.7M (8-bit), CIE1931 72%
Response Time: 6.5 (G to G)
Frequency: 60Hz
Lamp Type: WLED Embedded (LED Driver)
Signal Interface: LVDS (2 ch, 8-bit), 51 pins
Voltage: 12.0V