TCL 55" QLED - LED Backlight Strip Replacement (October 2025)

TCL 55R745 came in with dark spots and uneven backlight. Classic LED strip failure.

TCL QLED TVs use edge-lit LED backlighting. When the strips fail, you get dark spots or complete sections going out.

Identifying the Problem

Dark spots in the bottom corners. Uneven brightness across the screen. The picture was visible but the backlight was clearly failing.

This is a telltale sign of LED strip degradation or failure.

Diagnosis Process

Opened it up. The LED strips were clearly the problem. Some LEDs were completely dark. Others were flickering.

The strips are soldered to the driver board. You can't just replace individual LEDs - you have to replace the entire strip.

The Repair

Carefully desoldered the old LED strips. Cleaned the pads. Installed new LED strips with the same specifications.

Made sure the polarity was correct. LED strips are directional - reverse polarity and they won't light up.

Used fresh solder and proper flux for reliable connections.

Testing and Verification

Powered it up. All LEDs lit up. Brightness was even across the entire screen. No dark spots.

Let it run for 24 hours to make sure everything was stable.

Cost Analysis

New LED strips: $40 Labor: 1 hour Total: $90

New TCL QLED TV: $400+

The customer saved $300+ by repairing instead of replacing.

Why This Happens

LED strips degrade over time. Heat, voltage spikes, and manufacturing defects all contribute to failure.

TCL TVs are particularly prone to this because they use budget LED strips. But the repair is straightforward if you have the right parts.