The model name 8709 "PML" refers to Philips mini-LED technology, but can we really call its backlighting that? In the 65-inch version, we counted only 96 local dimming zones. For mini-LED standards, this number seems too low, which raises questions as to whether we are actually dealing with a true mini-LED here. However, if we look at the black quality, the television performs quite well. On the first two test patterns, as well as in less demanding scenes, the picture is quite decent – blacks are deep and contrast is satisfactory. Problems begin, however, in more complex scenes, such as the last three test patterns, where small light elements appear on the screen. The local dimming algorithm seems to "get lost," unable to decide whether to brighten or darken a given area. The result is visible errors – reduced black quality and unevenness of the picture. An example of the local dimming zones' operation can be seen in a scene from the film Sicario 2. You can see how the dimming zones try to reproduce details, but at the same time, this leads to a slight brightening around the helicopter lights. However, despite these shortcomings, the black level in the Philips PML8709 is quite good, especially considering its price class.
Moving on to picture quality tests, it is immediately apparent that the biggest change the TCL A400 Pro brings compared with typical lifestyle TVs is in blacks and contrast. This is all down to a full Mini-LED backlight placed directly behind the panel. As a result, the TV can locally dim selected parts of the image and is not limited solely to the native contrast of the panel. In the 65-inch sample we tested, we counted 180 dimming zones. That is not an impressive number compared with conventional Mini-LED TVs, where zones can be many times more numerous, but for a lifestyle TV it is already a very large step forward. Especially as competing models often either lack advanced local dimming or use much simpler edge-lit backlights.
In practice this produces very good results. In simpler scenes, where bright elements are clearly separated from a dark background, the A400 Pro can effectively dim the black areas of the image and show genuinely deep black. It is one of those things that immediately sets it apart from many conventional “picture” TVs. Of course, this does not mean TCL entirely avoids the limitations of Mini-LED LCD technology. 180 zones is still relatively few, so in more complex scenes, for example those with many small bright elements on a dark background, a halo effect can appear. It can also happen that blacks take on a more navy‑blue to purple tint in such conditions, because the TV cannot dim the background with the same precision as OLED TVs. Despite these limitations, we believe the A400 Pro brings a genuinely fresh breath to this category. For a lifestyle TV, which is primarily intended to look good on the wall, the level of blacks and contrast is a very strong selling point.
NOTE. It is worth noting that the number of local dimming zones depends on the screen diagonal. Larger variants should have more, but because the number of zones increases with panel size, we do not expect large differences in black level and contrast between the Mini-LED versions. The exception are the 32- and 43-inch models, in which TCL did not implement local dimming. These are significantly simpler LCD designs, so our review does not directly apply to those diagonals, and the prices quoted with the review should be treated as indicative only.
Number of dimming zones in the TCL A400 Pro
Screen size | Backlight type | Number of local dimming zones |
32" | PFS LED | No local dimming |
43" | PFS LED | No local dimming |
55" | QD Mini-LED | 112 zones |
65" | QD Mini-LED | 180 zones |
75" | QD Mini-LED | 240 zones |
85" | QD Mini-LED | 264 zones |
98" | QD Mini-LED | 448 zones |