Parameters need to be carefully checked to avoid the situation of TV 'broken after warranty'

TV technology is getting more and more modern every year, especially on high-end TV lines. However, cheap TVs are still popular because they meet most basic usage needs.

Backlighting is one of the factors to consider when buying a TV. Common technologies on LED TVs include direct-lit, full-array, or edge-lit.

Many mid-range and budget TVs use edge lighting. As the name suggests, these TVs use LEDs that line the sides of the TV. The strips are glued to a heatsink frame that sits on the back of the TV.

Despite some advantages, the way the components are arranged makes edge lighting technology not very durable, which can make users hesitate when buying a new TV, especially a cheap one.

An edge-lit TV with a broken backlight even though it's still powered on. Photo: Rtings .

Reasons not to choose edge-lit TV

Rtings , one of the famous electronics review sites, has been running durability tests on 100 LCD TVs since October 2022. As of February 2025, the results show that TVs using edge-lit technology fail sooner than models using other backlight technologies.

After a period of testing, edge-lit TVs are prone to curved reflectors, cracked light guides, and burned-out LEDs. These problems occur after long-term use at maximum brightness, significantly affecting durability.

Backlight failure is getting worse on some TVs after 2 years of testing. Photo: Rtings .

After more than 2 years of testing, the most affected LED TV models with backlight include Hisense H8G (full-array technology), LG QNED80 2022, Samsung Q60B QLED (all using edge-lit) and Vizio M6 Series Quantum 2021 (direct-lit).

According to Rtings , it's likely that users of these four models have either repaired or purchased another TV, as the backlights are so worn out that they're almost unwatchable.

Previously, as of July 2024, testing showed that of 10 edge-lit TVs, 7 had uniformity issues (64%), one was completely broken, and the rest showed signs of failure. In contrast, only 14 of 71 full-array or direct-illuminated TVs had the same problem (20%).

If you are buying a new TV and are focused on durability, users are advised to prioritize choosing a TV with direct-lit technology or full-array local dimming (FALD) due to better heat distribution.

Cracked light guide plate on Samsung AU8000 using edge lighting technology. Photo: Rtings .

Some TVs also incorporate local dimming technology. This technique improves contrast by dimming the backlight where the image is darker, creating deep blacks and improving the overall viewing experience.

Lighting technology is one factor that affects local dimming. Some edge-lit TVs tend to dim less precisely, causing the entire vertical (or horizontal) LED area to light up when a bright object appears.

For example, the LG QNED85T uses only 6 dimming zones on the edge-lit strip. This makes it easier for users to notice changes in brightness as objects move across the screen, especially from one bright area to another.

Some TVs using edge lighting technology, equipped with local dimming, have a problem of the lighting area being too wide even when only a small bright object appears on the screen. Photo: Rtings .

According to Rtings , TVs with full-array backlighting technology have better local dimming performance. In return, some edge-lit TVs have more uniform black levels than some full-array TVs.

In the same vein, technology site Tom's Guide advises users not to opt for edge lighting when buying a budget TV, especially if the price is under $500 .

The main reason also comes down to picture quality. Edge-lit TVs can struggle to reproduce contrast, especially when displaying dark images.

Other factors to consider

Aside from edge-lit panels, another factor to avoid when buying a budget TV is a resolution lower than 4K, especially if the size is over 40 inches.

While 4K TV isn't exactly cutting edge, streaming platforms now support 4K, so larger TVs will benefit from the higher resolution.

To ensure the TV supports 4K, users should pay attention to the terms 4K and UHD, avoiding phrases like FHD, 1080p or 720p.

Also, stay away from TVs with less than 3 HDMI ports. Because the sound quality may not be good, users often connect the TV to external speakers (commonly soundbars) via HDMI, not to mention devices such as game consoles or set-top boxes.

Some common connection ports on TV. Photo: Shutterstock .

Many people tend to keep their TVs for a long time before replacing them, so having a TV with multiple HDMI ports can save you trouble when your connectivity needs increase in the future.

Next, users should abandon the notion of choosing a “non-smart TV.” According to Tom’s Guide , the number of TVs that do not support the Internet is very small. That can make it difficult to choose, even ignoring good quality models just because they are smart TVs.

If you are worried about cheap TVs running slowly, you can completely ignore smart features, or buy set-top-boxes if you need an Internet connection.

Source: https://znews.vn/cong-nghe-nen-tranh-khi-mua-tv-gia-re-post1540674.html