What you'll notice
Sound plays normally but the screen stays black, or an on-screen message about protected content appears.
Why it happens
The HDCP copy-protection handshake between decoder and TV has failed — commonly because of a marginal cable, a soundbar or HDMI switch in the chain, or devices powered on in the wrong order.
HDCP is copy protection negotiated over the HDMI cable. When it fails you get audio without video, which looks far more serious than it is.
The order fix, first
Switch everything fully off. Switch the TV on first, wait for it to settle, then switch the decoder on. HDCP negotiation happens at connection and is genuinely order-sensitive. This alone resolves a large share of cases.
Take the middle out
Soundbars, AV receivers and HDMI switches all have to pass the handshake through, and cheaper ones frequently do not do it reliably. Connect the decoder directly to the TV. If the picture returns, the middle device is your culprit — and the fix is usually a firmware update on it, a different HDMI port, or routing video direct to the TV with audio taken separately.
Cable quality
Long or cheap HDMI cables fail handshakes intermittently, particularly at 4K. If the fault appears only after the room has warmed up, or only sometimes, suspect the cable before anything else. For runs behind a wall-mounted TV we fit active or optical HDMI as standard, because replacing a cable inside a wall is not a job anyone wants to do twice.
Ports are not identical
On many TVs only some HDMI ports support the full feature set. Moving to HDMI 1 is a thirty-second experiment that occasionally solves the whole thing.
How we fix it
We isolate the chain, correct the power-on order, substitute the cable, and identify which device in the path is failing to pass the handshake through.
Still not working?
If the checks above haven't restored your hdmi & tv connection, this usually needs a technician. Our TV Wall Mounting service covers exactly this fault — from R520, quoted upfront.