Samsung Galaxy A12 (A125F) Display Light Solution - Backlight Jumper & Repair Guide

 

Samsung Galaxy A12 (A125F) Display Light Solution

If your Samsung Galaxy A12 (SM-A125F) turns on but the screen is dark or dim (you can only see faint graphics under light), it means the backlight circuit is faulty. This guide will help you fix it.

Common Causes of A125F Display Light Problems

• Faulty LCD / Backlight LEDs
• Burnt coil or filter
• Shorted diode or capacitor
• Damaged backlight IC
• Loose or corroded display connector

Step-by-Step Repair Guide

1. Test with a known good LCD first.
2. Check and clean the LCD connector with IPA.
3. Test backlight coil and replace if open.
4. Check diode and capacitors for short.
5. Measure V_LED+ (15–25V expected).
6. Replace backlight IC if no output.

Samsung A125F Display Light Jumper Diagram

Refer to the image below for jumper ways and test points:

FAQ

Why does my Samsung A12 screen show faint graphics but no light?

Because the backlight circuit is faulty. The phone still displays images, but the LEDs don’t light up.

How do I check the backlight circuit?

Use a multimeter to test coil, diode, capacitors, and measure V_LED+. If missing, replace backlight IC.

Can replacing the LCD fix it?

Yes, sometimes only the LCD backlight is bad. Always test with another screen first.

What is the jumper solution?

Reconnect V_LED+, BL_EN, and GND lines using the jumper diagram to restore light.

Final Words

Most cases are solved by replacing the backlight coil or IC. If still not working, carefully trace jumper ways using the diagram provided.