Primarily found in 32-inch to 43-inch LG LED TV models (e.g., 32LJ500B, 43LJ5000, and similar series).
Typically driven by an LA7840 or TDA8351 IC.
Here are the schematic diagrams for the LJ7 chassis: lg lj7 chassis service manual
The Switch-Mode Power Supply (SMPS) converts the AC mains voltage into the isolated DC voltages required by the television.
| Pin | Signal | Voltage (Standby) | Voltage (On) | | :--- | :--- | :--- | :--- | | 1-2 | GND | 0V | 0V | | 3 | 3.5V_STBY | 3.5V | 3.5V | | 4 | PWR_ON | 0V | 3.3V | | 5 | DRV_ON | 0V | 3.3V | | 6-8 | 12V_SW | 0V | 12V | | 9-11 | 20V_SW | 0V | 20V | | 12-13 | GND | 0V | 0V | | 14 | N.C. | - | - | Primarily found in 32-inch to 43-inch LG LED TV models (e
This report summarizes the essential technical and maintenance data for LG televisions utilizing the (often associated with the LJ71A sub-designation), as found in models like the 1. Service Manual Core Components
This is commonly caused by a faulty power supply. Check the PSU for proper voltage output, especially on the LED backlight driver. | Pin | Signal | Voltage (Standby) |
If you're a technician or a DIY enthusiast tackling a malfunctioning LG TV, one of the first things you'll need is the appropriate service manual. This guide provides a deep dive into the world of the —what it is, the TVs it covers, common problems it can help you solve, and how to use it for effective repairs.
Alternative Method: Try pressing on both the chassis and the remote control simultaneously. Navigation and Saving Channel Up/Down (