According to Rtings' ongoing longevity test, which includes 100 TV models across various brands, thin LCD TVs with edge-LED backlighting tend to fail faster than other types of TVs.

We missed the article, published on July 26, over the summer, but the results are noteworthy. The 100 TVs have now accumulated over 10,000 hours of operation, equivalent to about 6 years of typical household use.

The accelerated longevity test spans various types of LCD TVs – edge-LED, direct LED and full array local dimming (FALD) – as well as OLED models.

In edge-lit LCD designs, LED backlights are usually positioned at the bottom edge, with a diffuser film to help spread light across the LCD panel. This technology is commonly used in thin mid-range TVs.


Issues with edge-LED LCD TVs
Rtings noted that over 25% of LCD TVs tested, regardless of backlight type, exhibit visible light uniformity issues that affect picture quality. For edge-LED LCD models, the figure rises significantly with 64% showing uniformity problems.

- "The results of this investigation are unequivocal: edge-lit TVs are inherently prone to significant durability issues, including warped reflector sheets, cracked light guide plates, and burnt-out LEDs due to concentrated heat," said testing site Rtings.

This statement applies solely to issues with the LED backlight, excluding electronic or electrical failures.

- "It didn't take 10,000 hours for issues to appear on our tested edge-lit TVs. Of the seven with visible uniformity issues, three started showing signs of deterioration at 2,200 hours of testing or sooner, which is around one year of use for a typical U.S. household," said Rtings.


 The edge-LED LCD models tested, with some showing issues after just 2200 hours. Photo: Rtings

Why is it happening?
Thermal imaging from the test reveals that edge-LED LCD TVs run significantly hotter along the bottom edge where the LEDs are concentrated. In contrast, direct-lit LCD models, with LEDs positioned behind the LCD panel, distribute heat more evenly.

In one case, the heat generated by the LEDs even melted part of the TV's bottom edge.

- "(T)he (Samsung) AU8000 was our first test subject. Upon opening and investigating the uniformity issues on four other Samsung and two LG models, we quickly realized that the issues are nearly identical across all the edge-lit TVs in our test, regardless of the manufacturer or model, because their fundamental design is identical."


Samsung disagrees
Most of the affected models in the test were from Samsung, due the brand's market share. In a statement, Samsung said that it does not agree that edge-LED technology has a higher failure rate.

- "Edge-lit technology has been reliably used in our LCD products for over 15 years, showing durability comparable to direct-lit models in real-world conditions. We have continuously improved the optical components and thermal management of edge-lit models, subjecting them to over 20 long-term reliability tests, including high-temperature testing. We remain dedicated to ongoing technological development to further enhance product quality," Samsung Electronics said in a statement to Rtings.

While edge-LED LCD TVs were once notably thinner than direct-LED LCD models, advancements have allowed manufacturers to slim down direct-LED designs significantly in recent years.

The full longevity test can be found here and you can check if a specific TV model uses edge-LED technology in FlatpanelsHD's TV database here.