Technical description and composition of the LG 26LB76-ZF TV, panel type and applicable modules. The composition of the modules.LG
Model: 26LB76-ZF
Chassis / Version: LD73C
Panel: V260B1-L03 RevC3
Inverter (backlight): VIT70038.50 Rev3
PWM Inverter: OZ964SN (20) AS324M-E1 (14)
MOSFET Inverter: D413 BA751L, D454 BA753F
Power Supply (PSU): EAX31845101 EAY3303030
PWM Power: FA5501A (PFC), U3037M (8), 4468TN (8), LAF001 (8), ICE38365J (8)
MOSFET Power: W20NM60, P9NK60Z, 62T03GH
MainBoard: 82EBR010-9606 GNM8215-06964
IC MainBoard: FLI8548H-LF
Tuner: TDFC-G107P
Specifications 26LB76
LG 26LB76-ZF
General recommendations for repairing TV LCD
Repair and diagnostics of any electronic device, in particular LG with the LD73C chassis, it is advisable to start with a careful external examination of internal and external elements. In some cases, visible external damage to the elements can suggest the direction of troubleshooting and localization of the defect even before the start of the necessary measurements at the control points of the nodes of electronic circuits. Electrolytic capacitors of filters with a swollen body, as well as ring cracks or a layer of coal on burned-out resistors formed in soldered leads of heated elements, sometimes tell the repairman the causes of the malfunction and possible consequences.
If the EAY3303030 EAX31845101 power supply module fails, the external manifestations may be different, for example, the LG 26LB76-ZF does not turn on at all and there is no indication of the indicator lights on the front panel. With the same symptoms, the stabilizer (converter) of the power supply to the control processor may be faulty. In the absence of swollen filter capacitors of the secondary rectifiers, the diagnostics of the power supply should be started by checking the fuse and, if it is broken, it is first necessary to check all the power semiconductor elements of the primary circuit - diodes and transistors 62T03GH for the possibility of avalanche or thermal breakdown.
Mos-Fet keys used in switching power supplies (SMPS) rarely fail for no reason to look for when checking other circuit elements. Often the breakdown is caused by malfunctions of electrolytic capacitors or semiconductor elements in the primary circuit, or by a break in the resistors in the stabilization circuits. The PWM controller chip 5501 (8) U3037M (8) 4468TN (8) LAF001 (8) ICE38365J (8) can also cause a breakdown of the power switch of the converter.
In cases where the LG 26LB76-ZF TV has lost an image, and the sound is there and all the other functions are functional, there is a possibility of a malfunction of the inverter (converter for powering the backlight). When you turn on the TV, the image may appear briefly and immediately disappear. It must be borne in mind that with such manifestations, the lamps themselves also fail, the malfunction of which can be detected by replacement, by connecting to the connectors for diagnostics that are known to be serviceable and suitable in power. When diagnosing a malfunction of the inverter with the protection turned off, special care must be taken, because there is a risk of failure of the power elements of the inverter. After the diagnosis, it is imperative to restore the protection circuits for the inverter to operate normally.
When trying to repair the motherboard, you should first check the serviceability of linear stabilizers or power converters of microcircuits and, if necessary, update the software (software). Often, the MB (SSB) card must be replaced in case of complex malfunctions that are difficult to detect. When trying to repair, you should check its elements - FLI8548H-LF and replace failed chips with new ones. Some malfunctions may be due to the use of BGA soldering technologies in modern Main Board technologies. Typically, such defects are detected by local heating of the chip.
Once again, we remind TV users: you should not make attempts to repair it yourself without the appropriate knowledge, experience and the necessary qualifications! Trust the repair only to professionals with sufficient experience in the field of electronic equipment repair.
SCHEMATIC MANUAL ---------------------------> LG 26LB75, 26LB75-ZE, 26LB76, 26LB76-ZF Chassis LD73C.
On the 26LB76-ZF TV, the EAX31845101 power module is installed using the PFC (Power Factor Correction) scheme acting as an active filter to eliminate the higher harmonic components of the current consumption. The step-up converter based on the 5501 PWM controller does not allow the input rectifier filter's electrolytic capacitor to be connected to the network directly through open diodes, when the reactance (about 15-30 ohms at a frequency of 50 Hz) determines the charge current. As a result of the conversion, the charging current of the capacitor will be determined in such a way that the envelope of the high-frequency pulses of the input current will repeat the phase and shape of the sine wave of the input voltage. The health check of the PFC unit is carried out by measuring the DC voltage on the capacitor of the rectifier network. In operating mode, it should be around 380V, in standby approximately 300V.The appearance of the power supply
Main features of the device LG 26LB76-ZF:
Installed matrix (LCD panel) V260B1-L03 RevC3.
To power the backlight, an inverter VIT70038.50 is used, it is controlled by the PWM controller OZ964SN (20) AS324M-E1 (14). As power elements of the inverter, keys of the type D413 BA751L, D454 BA753F are used.
The necessary supply voltages for all nodes of the LG 26LB76-ZF TV are generated by the EAX31845101 power module or its analogs using the FA5501A (PFC), U3037M (8), 4468TN (8), LAF001 (8), ICE38365J (8) microcircuits and power switches type W20NM60, P9NK60Z, 62T03GH.
MainBoard - the main board (motherboard) is a 82EBR010-9606 module, using FLI8548H-LF chips and others.
The TDFC-G107P tuner provides TV reception and channel tuning.
Additional technical information about the panel:
Brand: CMO
Model: V260B1-L03
Type: a-Si TFT-LCD, Panel
Diagonal size: 26.0 inch
Resolution: 1366x768, WXGA
Display Mode: TN, Normally White, Transmissive
Active Area: 575.769x323.712 mm
Surface: Antiglare (Haze 25%), Hard coating (3H)
Brightness: 500 cd / m²
Contrast Ratio: 800: 1
Display Colors: 16.2M (6-bit + FRC), CIE1931 72%
Response Time: 3/5 (Tr / Td)
Frequency: 60Hz
Lamp Type: 12 pcs CCFL Embedded (Inverter)
Signal Interface: LVDS (1 ch, 8-bit), 30 pins
Voltage: 12.0V