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Video problem

Black screen at 4K120 or with VRR

The image drops out, flickers, or 120 Hz is not offered at all. This is nearly always bandwidth - and bandwidth has four possible bottlenecks.

First, the question that settles half of these cases

Which model do you have? The original Arcana is HDMI 2.0b at 18 Gbps. That is enough for 4K60, and it is not enough for a 4K120 FRL signal — not with a better cable, not with a different setting. If a PS5, an Xbox Series X or a gaming PC is trying to output 4K120 through an original Arcana, a black screen is the correct behaviour, and no amount of configuration will change it. That path needs the Arcana 2, which does FRL5 at 40 Gbps.

If you already have an Arcana 2 and still get a black screen, read on.

The cables

This is the single most common cause on an otherwise correct chain, and the most commonly dismissed. 4K120 with HDR and VRR is a genuinely demanding signal. What matters:

Rating. Ultra High Speed HDMI, rated 48 Gbps. “4K” or “High Speed” on the packaging is not the same thing and will not carry FRL reliably.
Length. Passive copper gets marginal beyond about three metres at these rates. Longer runs want an active optical cable.
Every link in the chain. The Arcana 2 has a cable in and a cable out. One good cable and one old one gives you the old one's performance.
Sharp bends. A tight bend behind a wall-mounted TV degrades a marginal cable enough to matter.

The fastest diagnostic here: temporarily drop the source to 4K60. If the picture returns, the chain works and the problem is bandwidth — which means cables, unless you are on the original Arcana.

The display's HDMI port setting

Nearly every TV ships with its HDMI ports in a reduced-bandwidth mode, and you have to enable the full mode per port. It is not on by default and it is easy to miss because the name gives no hint:

Samsung — Input Signal Plus (in some model years: HDMI UHD Colour)
LG — HDMI Deep Colour, sometimes shown as 4K@120 Hz
Sony — HDMI signal format › Enhanced format
Philips — HDMI Ultra HD, set to Optimal
Panasonic — HDMI Auto / 4K signal format

Two things people trip over: the setting is per port, so enabling it on HDMI 1 does nothing for HDMI 3; and on many TVs only two of the four ports are full-bandwidth HDMI 2.1 in the first place. Check the manual for which ports those are.

The source

PlayStation 5 — Settings › Screen and Video › Video Output. Leave Resolution, 120 Hz Output and VRR on Automatic, then run the built-in HDMI test, which reports what the chain actually negotiated.
Xbox Series X — Settings › General › TV & display options. The 4K TV details screen there lists which formats the chain reports as available, which is diagnostic in itself.
Gaming PC — check that the GPU driver is actually offering 120 Hz at the resolution you want, and be aware that DSC support varies between GPU generations.

Handshake and HDCP

HDMI negotiates once, at power-up, and a failed negotiation stays failed until you force a new one. After any change: everything fully off, then display first, Arcana second, source last. If the picture drops out only when protected content starts, that points at HDCP rather than bandwidth — the Arcana's OLED display shows the HDCP state on both ports, which tells you which side is refusing.

Try scaling as a diagnostic

The Arcana 2 can up- and downscale. Forcing a downscale to 4K60 on the output is a fast way to isolate the fault: if the picture is stable that way, the video path and the audio path are fine and you are looking squarely at a bandwidth limit on the output side.

When it works but flickers

Intermittent blackouts of a second or so during gameplay are usually VRR rather than bandwidth. Turn VRR off temporarily; if the flickering stops, you are looking at a VRR range mismatch between source and display rather than at the Arcana. Some displays also show this only within a specific refresh-rate window.

Frequently asked

Can the original Arcana do 4K120?

Not as a full FRL chain. It is HDMI 2.0b at 18 Gbps, which covers 4K60. It does handle 1080p120 and 1440p120. For 4K120 and VRR you need the Arcana 2.

My cable says 4K, is that good enough?

For 4K60, usually. For 4K120 with HDR and VRR, no. You want a cable certified Ultra High Speed at 48 Gbps, and preferably under three metres if it is passive copper.

Why does it work at 4K60 but not 4K120?

Because that is a bandwidth boundary. 4K60 fits in 18 Gbps; 4K120 needs FRL and considerably more headroom. Something in the chain - the Arcana model, a cable, or the TV's port mode - is capping you below it.

The picture flickers every few minutes. Bandwidth?

More likely VRR. Switch VRR off for a moment: if the flickering stops, it is a VRR range mismatch between source and display, not a capacity problem.

Do I need to enable something on my TV?

Almost certainly. Most TVs ship with HDMI ports in reduced-bandwidth mode and require the full mode to be switched on per port - Input Signal Plus on Samsung, HDMI Deep Colour on LG, Enhanced format on Sony.

Which Arcana do you need for this?

Arcana 24K120 and VRR need HDMI 2.1 at FRL5, 40 Gbps. Arcana 2 passes those signals through and can still extract the full audio for your sound system. This is the one case where the original model is genuinely not enough.

FirstRule out the cables. A cable rated for 18 Gbps gives exactly this symptom on a 4K120 signal, and swapping it costs a fraction of a new device. Work through the steps above before you order anything.

The original Arcana is an 18 Gbps device. Some limited 4K120 modes fit inside that, but modern 10-bit HDR and VRR signals do not.

Buy the Arcana 2 at HDfury.eu Compare both models