The LG 50LN5700 is a 50-inch LED TV with Full HD 1080p resolution, built-in digital tuner, multiple HDMI inputs, USB connectivity, Smart TV features, energy saving modes, and advanced picture and sound settings. This service manual provides comprehensive technical information for service technicians including disassembly procedures, circuit diagrams, troubleshooting guides, and replacement parts information.
Technical specifications and main features of the LG 50LN5700 LED TV.
| Specification | Details |
|---|---|
| Screen Size | 50 inches LED |
| Resolution | 1920 x 1080 Full HD |
| Panel Type | IPS LED |
| TV System | ATSC/NTSC/QAM |
| Inputs | 3x HDMI, 2x USB, Component, Composite, RF |
| Sound Output | 10W x 2 |
| Power Consumption | 70W (typical) |
| Standby Power | Under 0.5W |
| Operating Voltage | AC 100-240V, 50/60Hz |
| Dimensions | 1127 x 655 x 49.5mm (without stand) |
Important safety instructions for service technicians.
WARNING! High voltage present in power supply and inverter sections. Exercise extreme caution when servicing.
Step-by-step instructions for disassembling the TV unit.
CAUTION! Handle LCD panel carefully to avoid cracking or damaging the glass substrate.
Detailed information about the main board and its components.
Power supply board specifications and troubleshooting.
Model: EAX64936801
Output Voltages: +12V, +24V, +3.3V_STBY, +5V_STBY, +18V, PWR_ON
Common Issues: No power, intermittent power, backlight issues, voltage fluctuations.
Test Points: Check all output voltages under load, inspect capacitors for bulging, check fuse continuity.
LED backlight specifications and service procedures.
LED Type: Direct LED backlight with 4 strings
LED Driver: Integrated on power supply board
LED Current: 120mA per string typical
Troubleshooting: Check LED driver output, test individual LED strings, inspect for dark spots or uneven lighting.
Timing Controller board information and diagnostics.
Model: EBT65019302
Function: Processes video signal for LCD panel
Common Symptoms: Vertical/horizontal lines, no picture, distorted image, color issues
Voltages: VGH: +28V, VGL: -6V, VCOM: +6V, VDD: +3.3V
LCD panel technical specifications.
Tip: Handle panel edges only, avoid pressure on screen surface.
Systematic troubleshooting procedures for common issues.
| Problem | Diagnostic Steps | Solution |
|---|---|---|
| No Power | Check AC input, fuse, standby voltage | Replace power board if no standby voltage |
| No Picture/Sound | Check main board voltages, backlight operation | Replace main board or T-con board |
| Backlight Issues | Test LED strings, check driver circuit | Replace LED strips or power board |
| Image Artifacts | Check T-con board, LVDS cable | Reseat cables, replace T-con board |
| No Sound | Check audio IC, speakers, connections | Replace main board or speakers |
Diagnostic error codes and their meanings.
| Error Code | Description | Action |
|---|---|---|
| ER-00 | Main board communication error | Check main board connections |
| ER-01 | T-con board error | Replace T-con board |
| ER-02 | Panel error | Check panel connections |
| ER-03 | Power supply error | Check power board voltages |
| ER-04 | Backlight error | Check LED backlight system |
Authorized replacement parts for LG 50LN5700.
Service Contact: LG Service Center 1-800-243-0000
Technical Support: www.lg.com/us/support