Mini LED is only as good as the control behind it, and the A400M is the TCL model where that control comes with a published figure: 112 dimming zones for the 55-inch, set behind an HVA panel in a flat-back cabinet just 39.9mm deep. Add a 144Hz native panel, four HDMI 2.1 inputs and ONKYO-branded sound, and you have a 55-inch that suits a slim wall mount in a bedroom as well as a gaming corner.
Key features
112 dimming zones and 600 nits
TCL's Hong Kong spec sheet lists 112 local dimming zones and a brightness rating of 600 nits for the 55-inch A400M. Zone dimming darkens the backlight behind dark parts of the picture while keeping bright areas lit, which is what lifts contrast in night scenes beyond a panel-only QLED set. TCL's halo-control design uses condensed micro-lenses and Micro-OD optics to keep light from spilling around bright objects.
QD-Mini LED over an HVA panel
The backlight sits behind an HVA panel rated at 5000:1 native contrast, with a quantum dot layer covering up to 93% of DCI-P3. HDR10+ and HLG are supported; HDR10+ carries dynamic metadata, so brightness mapping adjusts scene by scene. Picture processing is handled by TCL's TSR AiPQ processor.
144Hz native, 288Hz VRR and FreeSync Premium Pro
The panel runs at 4K 144Hz natively, and TCL's Game Accelerator offers 288Hz at 1080p, with a VRR range of 48–288Hz. Four HDMI 2.1 inputs, eARC and AMD FreeSync Premium Pro certification mean tear-free variable refresh rate gaming from a PS5, Xbox Series X or PC, and Game Master puts frame rate and VRR status on screen.
39.9mm flat-back cabinet and ONKYO sound
The flat unibody back is 39.9mm deep at 55 inches, so on a slim bracket the set sits close to the wall — useful in a bedroom or corridor where a protruding TV gets in the way. Audio is an ONKYO sound system in a 20W 2.0-channel layout with Dolby Atmos, DTS:X and DTS Virtual:X. Google TV with Gemini, AirPlay 2, Wi-Fi 5, Bluetooth 5.4 and a built-in DTMB tuner complete the package.
Deciding between 55 and 65 inches? Our TV size calculator matches screen size to your seating distance.
Specifications
| Specification | Detail |
|---|---|
| Screen size | 55 inches |
| Panel / backlight | QD-Mini LED, HVA panel |
| Dimming zones | 112 |
| Brightness | 600 nits |
| Native contrast | 5000:1 |
| Resolution | 3840 x 2160 (4K UHD) |
| Native refresh rate | 144Hz |
| VRR | VRR 48–288Hz, DLG 288Hz Game Accelerator, AMD FreeSync Premium Pro |
| Colour gamut | Up to 93% DCI-P3 |
| HDR formats | HDR10+, HLG |
| Audio | ONKYO sound system, 20W 2.0 channel, Dolby Atmos, DTS:X, DTS Virtual:X |
| Picture processing | TSR AiPQ Processor |
| Smart platform | Google TV with Gemini, 32GB storage, AirPlay 2 |
| HDMI | 4 x HDMI 2.1 (eARC) |
| USB | 1 x USB 2.0, 1 x USB 3.0 |
| Tuner | Built-in digital terrestrial tuner (DTMB) |
| Wi-Fi | Wi-Fi 5 (802.11ac) |
| Bluetooth | 5.4 |
| Dimensions without stand | 1228 x 710 x 39.9 mm |
| Dimensions with stand | 1228 x 758 x 295 mm |
| Net weight | 12.5 kg with stand, 12.1 kg without |
| VESA wall mount | 400 x 400 mm |
| Energy label | Grade 2 |
For the flattest fit on the wall TCL notes that an ultra-slim bracket is needed. Specifications not listed here are not published by TCL, and we do not fill in figures that are not official.
Who it's for
- Anyone wall mounting a 55-inch in a bedroom or narrow room, where the 39.9mm flat back keeps the set close to the wall.
- Console and PC gamers who want HDMI 2.1, FreeSync Premium Pro and a 144Hz native panel at 55 inches.
- Buyers who want Mini LED local dimming with a published zone count, plus ONKYO-branded audio, which the 55-inch P8L does not have.
- Not for bright-room HDR fans. At 600 nits the A400M is well behind the 55-inch C7L and C8L, which are rated at 2,700 and 3,000 nits.
Warranty and delivery
This is Hong Kong licensed stock (行貨) carrying the manufacturer's Hong Kong warranty. The exact warranty term is stated on the warranty card supplied with the set. Viewing is available by appointment at our Kwun Tong showroom.
For a 55-inch set, delivery with tabletop installation is HK$300, or delivery with wall mounting is HK$600 with the bracket included. Collection at the Kwun Tong shop is free. Walk-up buildings without a lift add HK$100 per floor, with no cap. Discovery Bay adds HK$500. Cheung Chau and Lamma Island orders are delivered to the Central pier for self-collection, without installation. Installation is a paid service and is not included in the price of the set.
Frequently asked questions
How many dimming zones does the 55-inch A400M have?
TCL's Hong Kong specification lists 112 local dimming zones for the 55-inch. Larger sizes have more; TCL's "up to 240 zones" figure refers to the 75-inch model.
Does the A400M work with a PS5 at 120Hz?
Yes. The panel is 144Hz native with HDMI 2.1 inputs, so 120Hz console modes run at full frame rate, and AMD FreeSync Premium Pro handles variable refresh rate.
Does it need a set-top box for local channels?
No. The built-in digital terrestrial tuner receives Hong Kong free-to-air DTMB broadcasts directly from an aerial.