Technical description and composition of the LG 32LD750 TV, panel type and applicable modules. The composition of the modules.LG
Model: 32LD750 ZA
Chassis / Version: LD03B
Panel: LC320WUH (SC) (M1)
Inverter (backlight): integrated into PSU
Power Supply (PSU): EAX61131704 / 4
MainBoard: EAX61531909 (2)
IC MainBoard: LGE3556C, SAA35116504, SAA35042638, ST24C16, 25X40BVSIG
Tuner: TDFR-G135D
Control: AKB72914208
Specifications 32LD750
LG 32LD750
General recommendations for repairing TV LCD
Repair of electronic equipment usually begins with its external inspection and diagnosis of the malfunction. In this case, you should examine all the internal components of the LG 32LD750 ZA TV, as well as the external elements of the housing. Often, by the visible signs of a change in the state of some elements, one can judge the causes of the defect. Experienced repairmen are well aware of how ring cracks in soldered terminals look, swollen capacitors, and other causes of problems in electronic devices.
If the LG 32LD750 does not turn on, no control lights on the front panel light up or blink, therefore, there is a very high probability of a malfunction of the EAX61131704 / 4 power module. In some cases, only the processor power regulator may be faulty. When diagnosing and repairing the power supply, after replacing the swollen capacitors of the secondary rectifier filters (if any), you must first check the mains fuse. When it is broken, the power elements of transistors and rectifier bridge diodes should be checked for avalanche (thermal) breakdown.
The reasons for the breakdown of the power switch in switching power supplies (IIPS) can be different, for example, a malfunction of semiconductor cells or electrolytic capacitors in the stabilization circuits of the primary circuit, as well as a failure in the operation of the PWM controller chip or broken resistors in its bundle.
If the LG 32LD750 does not have an image, but there is sound and the TV is controlled by the remote control, a malfunction in the display backlight nodes is likely. The lamps or the power converter - inverter may be faulty. Often in such cases, when you turn on the TV, an image appears and immediately disappears. First of all, it is necessary to verify the operability of the electrolytic capacitors of the rectifier filter supplying the inverter, and check the LCD lamps by connecting external and obviously serviceable for diagnosis to the connectors. If in diagnosing a malfunction, it is necessary to disable the inverter protection, there is a risk of failure of the power elements of the inverter, and special care is required during work, and after they are finished, it is necessary to restore the protection circuits for further safe operation of the TV by the owner in normal mode.
If the EAX61531909 motherboard is faulty (2), first of all it is necessary to check all the linear stabilizers and power converters of its chips, and also, if necessary, update the software (software). Sometimes you can check the health of MB only by replacement. When repairing an MB board, it is necessary to check its components LGE3556C, SAA35116504, SAA35042638. Defective items should be replaced. If chips with BGA soldering technology are used, a problem in its implementation is detected by the local heating of the chip.
If the TV works normally from external devices, but does not tune into television channels, the TDFR-G135D tuner may be malfunctioning. In such cases, first of all, you should make sure that there are supply voltages at its corresponding terminals. Sometimes the cause of the inoperability of the tuner may be a software failure.
Attention to the owners! Attempts at self-repair of the LG 32LD750 TV are not recommended by the manufacturer and can lead to serious negative consequences!Typical defects of LG TVs with LGE3556C processors are provoked by its severe temperature conditions and the quality of the LGE3556C processor itself.
External manifestations may be different - the tuner or external inputs do not work, or the TV does not turn on, for example, the control lamp blinks or hangs on the screen saver.
If, when the processor warms up, performance is restored, in such cases a reball can sometimes help. Then there is the opportunity to extend the life of the TV with the help of an additional heat sink or cooler.
When replacing the processor, it should be borne in mind that they are discontinued and all LGE3556C are sent by ALIexpress sellers, in most cases control units are often already faulty !!!!!!!!!!!!!!!!
SCHEMATIC MANUAL --------------------> LG Chassis LD03B; MODEL: 42LD750, 42LD750N, 42LD750, 42LD750N-ZA, 42LD790, 42LD790-ZA, 42LD751 42LD751-ZB
The appearance of the MainBoard EAX61531909 is shown in the figure below:EAX61531909
EAX61531909 can be used in TVs:
LG 32LD750 ZA (Panel LC320WUH (SC)(M1)), LG 32LD650 (Panel LC320WUG (SC)(A1)), LG 47LD750 ZA (Panel LC470WUH (SC)(M1)).
The appearance of the power supply
Main features of the device LG 32LD750:
Installed matrix (LCD panel) LC320WUH (SC) (M1).
To power the backlight, a converter is used, combined with a power supply.
The formation of the necessary supply voltages for all nodes of the LG 32LD750 TV is carried out by the EAX61131704 power module, or its analogues.
MainBoard - the main board (motherboard) is an EAX61531909 module, using chips LGE3556C, SAA35116504, SAA35042638, ST24C16, 25X40BVSIG and others.
The TDFR-G135D tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: LG Display
Model: LC320WUH-SCM1
Type: a-Si TFT-LCD, Panel
Diagonal size: 31.5 inch
Resolution: 1920x1080, FHD
Display Mode: S-IPS, Normally Black, Transmissive
Active Area: 698.4x392.85 mm
Surface: Antiglare (Haze 10%), Hard coating (3H)
Brightness: 500 cd / m²
Contrast Ratio: 1400: 1
Display Colors: 1.06B (8-bit + Dithering), CIE1931 72%
Response Time: 8/10 (Tr / Td)
Frequency: 120Hz + 120Hz
Lamp Type: 14 pcs EEFL Without Driver
Signal Interface: Mini LVDS, 120 pins
Voltage: 12.0V
