Start here
The quickest way to tell a dead screen from a dead signal
Press Volume or Home on the TV remote. If the on-screen menu or volume bar appears, the panel and backlight work and the fault is in your input, source device, or HDMI cable. If nothing appears at all, shine a flashlight close to the screen at an angle: a faint image means the picture is being drawn but the backlight has failed.
Applies to: LED, QLED, OLED and mini-LED televisions from Samsung, LG, Sony, TCL, Hisense, Vizio, Philips and Panasonic. Menu names differ by brand and model year — the paths below name the common ones.
Which of these matches your TV?
Sound with no picture almost always splits into two very different problems: the TV is showing nothing at all, or the TV is fine and the thing feeding it is not. The menu test below separates them in a few seconds, so start there rather than guessing. Test the same channel or app after each change, and stop once the picture returns.
No menu appears when I press Home
Is anything being lit on the screen at all?
Run the menu testThe menu shows, but my source is black
Is the TV on the input the device is actually plugged into?
Check the inputOnly one HDMI port is black
Does the same device work on a different port or cable?
Test cables and portsThe picture drops out after minutes or hours
Does a full power reset bring it back temporarily?
Power-reset everything2. Confirm the input and the source device
If the menu appeared, the TV works. Cycle through every input with the Source or Input button and watch for one that shows a picture. Samsung's instruction is to make sure the TV is set to the same source as the external device — if the cable box is in HDMI 1, the TV has to be on HDMI 1, and the box has to be switched on rather than in standby.
Built-in apps are a useful control test. Open Netflix, YouTube, or live broadcast TV from the TV's own menu. If those play with a picture and only the HDMI input is black, the television has been ruled out and the problem sits in the source device, the cable, or the handshake between them. If the built-in apps are also black while the menu overlay is visible, the fault is more likely a picture setting or a panel issue than an input problem.
Anything sitting between the source and the TV — an AV receiver, a soundbar with HDMI passthrough, a switch, an extender — is a common culprit, especially with 4K HDR content. Connect the source straight to the TV, bypassing that box entirely. If the picture returns, the middle device or its HDCP handling is at fault. This also explains the classic pattern where sound reaches the soundbar perfectly while the video never arrives.
3. Reseat and test the HDMI cable and ports
Samsung recommends unplugging and reconnecting the connections one cable at a time, from both ends of each cable, and inspecting them for physical damage before reconnecting. LG's version of the same step is to disconnect the HDMI cable from both the TV and the device, then reconnect it firmly, and to treat a cable that still fails as one to replace. Bent pins, a partially seated plug, and a cable pinched behind a wall mount all produce exactly this symptom.
Move the cable to a different HDMI port on the TV. A single dead port is a common, well-contained failure, and it makes the diagnosis obvious: if the source works on HDMI 3 but not HDMI 2, nothing else needs investigating. Then swap in a different HDMI cable, ideally a certified High Speed or Ultra High Speed one. Marginal cables often carry audio while failing to sustain the higher bandwidth video needs, which is precisely the sound-but-no-picture pattern.
Samsung TVs can test the cable for you: Settings → Support → Device Care → Self Diagnosis → Signal Information → HDMI Cable Test. Samsung notes it works best with cables under 6 feet, or 2 metres on One Connect Box models, and that a failed result means replacing the cable rather than booking service. If your set has a One Connect Box, check that its cable is firmly seated and undamaged too.
Long HDMI runs over about 5 metres are a frequent cause of video dropping while audio survives. If your cable runs through a wall or across a room, test with a short cable at the TV before concluding the TV is faulty.
4. Power-reset the TV and the source device
A power reset is not the same as switching off with the remote, which leaves the set in standby with the boards still energised. Unplug the TV at the wall. Sony's guidance for its Android TV and Google TV models is to leave it disconnected for around two minutes; Sony's no-picture article also describes unplugging the power cord for 30 seconds after disconnecting attached devices. LG suggests holding the physical power button on the TV itself for about 10 seconds while it is unplugged, which drains residual charge from the board.
Do the same for the source device — unplug the cable box, console, or streaming stick rather than putting it to sleep. Sony's article also has you disconnect other attached hardware, including USB drives and HDMI devices, so a single misbehaving device cannot hold the input in a bad state. Then power everything back up in order: TV first, let it fully boot, then the source.
If a power reset restores the picture but it disappears again later, note how long it takes. Minutes to hours before failing, then recovering after a cooldown, is a pattern worth reporting to a technician — it often points at a power supply or backlight driver degrading under heat rather than at anything you can fix with settings.
5. Rule out picture settings and firmware
Backlight and brightness set to zero produce a screen that looks dead but still passes a faint image under a flashlight, and energy-saving or ambient light sensor modes can dim a panel dramatically in a dark room. If your menu is visible, walk through Picture settings and raise Backlight or Brightness, then switch off eco or power-saving mode and any automatic brightness feature before concluding the hardware failed.
Samsung sets can also confirm the panel independently. Run the Picture Test: on 2022 and later models, Settings → Support → Device Care → Self Diagnosis → Picture Test; on 2016–2019 models, Settings → Support → Self Diagnosis → Start Picture Test. Samsung's rule for reading the result is simple — if the test photo displays correctly, the display is working and the problem is an external device or connection; if the test image does not appear or shows faults, the TV itself needs attention.
Update the TV's firmware if you can reach the menu, then, only if the picture is still missing, try a factory reset. A reset clears every picture setting, app login, and network configuration, so treat it as a last software step rather than an early one. It cannot repair a failed backlight, a dead port, or a bad cable.
Samsung
Settings → Support → Device Care → Self Diagnosis → Picture Test confirms the panel. The HDMI Cable Test under Signal Information checks the cable separately.
LG · Sony · others
Use the volume or Home overlay as the panel check, then compare a built-in app against the HDMI input. Reset options sit under General or System → Reset in most menus.
6. Backlight failure, service, and when repair is worth it
If the flashlight test showed a faint image, the diagnosis is effectively settled: the panel and the video board are working and the backlight, its driver, or the power supply feeding it has failed. Failed LED strips and power boards are standard repairs for a technician, but they mean opening the set. Do not attempt this yourself — a television's power supply stores a dangerous charge long after it is unplugged, and the panel itself cracks easily under uneven pressure.
Before booking service, check whether the set is still in warranty and whether the manufacturer's own support flow ends in a repair request, as Samsung's does when its cable and source checks do not resolve the black screen. Have the model number, the purchase date, and your test results ready.
Give support the evidence rather than the symptom. Say whether the menu appears, whether a flashlight reveals a faint image, whether built-in apps show a picture, which inputs and cables you tried, and whether a power reset helped even briefly. Those five answers separate a backlight fault from a port fault from a source fault, and they are the difference between a targeted repair quote and a diagnostic fee. On older or budget sets, weigh a backlight or power board quote against replacement — panel-related repairs can approach the price of a comparable new television.
Frequently asked questions
Why does my TV have sound but no picture?
Sound and video travel on separate paths, so one can survive while the other fails. The three common groups are a signal problem (wrong input, sleeping source device, marginal or damaged HDMI cable), a settings problem (backlight or brightness at zero, an aggressive eco mode), and a hardware problem (a failed backlight, power board, or HDMI port). The menu test in step 1 tells you which group you are in.
Does a black screen with working sound always mean the backlight is broken?
No. A failed backlight is one cause, but a wrong input, a bad HDMI cable, and a source device stuck in standby produce the same symptom and cost nothing to rule out. Only conclude backlight if the TV's own menu never appears and a flashlight held at an angle reveals a faint image on the screen.
Is the flashlight test safe for my TV?
Yes — you are only shining light onto the screen from a few inches away, not touching or opening anything. Do not press on the panel while you look, and use a normal torch or phone light rather than anything that produces heat.
Why is only one HDMI input black when the others work?
That pattern usually means a failed port, a bad cable on that port, or an HDCP handshake failure with the specific device plugged into it. Move the same device and cable to a working port. If it plays there, the port is at fault; if it stays black, test a different cable before suspecting the device.
Should I factory reset my TV to fix a black screen?
Only after the input, cable, and power-reset checks, and only if you can still see the menu to perform it. A factory reset clears picture settings, app sign-ins, and network setup, and it cannot repair a failed backlight, a dead HDMI port, or a damaged cable. Update the firmware first — it is the lower-cost software step.
Is it worth repairing a TV with a failed backlight?
It depends on the set's age, size, and the quote. Replacing LED strips or a power board is routine work for a technician, but on older or smaller televisions the labour can approach the cost of a replacement. Get a written quote that names the part before deciding, and confirm whether the set is still covered by warranty.
Sources and review notes
Checked on . Compiled by Glitchary from manufacturer troubleshooting documentation. Menu paths vary by brand and model year — check the manual for your exact model. The flashlight and built-in-app comparisons are diagnostic checks, not a guarantee of repair, and any work inside the television should be done by a qualified technician. Glitchary is independent of Samsung, LG, Sony, and the other manufacturers named here.