LED TV has sound but no picture: input, cables, settings and when to get service

Unplug the adapter or the plug from the wall socket before checking anything. Make sure your hands and the work surface are dry.

Capacitors keep an electric charge after the plug is pulled; this part is not opened at home.

Every check in this article is done from outside the TV. Do not open the TV's back cover.

Samsung names three possibilities for a TV with sound and a black screen: a connection problem, a problem with the device connected to the TV, or a failed part inside the TV. One simple test tells them apart.

Press the Home or Menu button on the remote. According to Samsung, if the menu appears, the TV is actually on but is not on the correct input source or is not receiving a signal. If the menu does not appear at all, the TV may have a power problem. If the menu only shows partly because the black area cuts it off, Samsung Philippines says to request service right away.

The wrong input source is the easiest cause to fix. According to the Sharp LED TV manual, you choose the input source with the INPUT button on the remote or on the TV. Its troubleshooting table asks the same question for no picture: is the selected input correct? Press INPUT a few times and pause a few seconds on each choice, because the TV needs time to recognize the signal.

Samsung points out a common trap. The screen can be black if the TV is connected to a device that is switched off. For example, if the set-top box is connected to HDMI 1, the TV must be set to HDMI 1 and the set-top box must be on.

In many Indonesian homes, digital TV comes in through a set-top box connected to the TV with an HDMI or composite cable. Watch the light on the set-top box. If the box is off or in standby, the TV only receives a blank screen even if sound was playing from another source. Turn the set-top box on, then select the matching input.

1. Turn the TV off before you disconnect or connect external equipment, as the Sharp manual asks.
2. Unplug and reconnect each cable, one at a time, at both ends. Samsung says to replace a damaged cable.
3. After reconnecting, turn the source device off and then back on.
4. On a Samsung TV that supports it, run the HDMI cable test through Settings, Support, Device Care, Self Diagnosis, Signal Information, then HDMI Cable Test. For models before 2020, Samsung says the menu is under Menu, Support, Self Diagnosis.
5. Try another device or another input port. If the TV can show a picture from another device or cable, Samsung says the TV is not the cause.

The Samsung HDMI cable test is designed for short cables and may not be accurate on long ones. If the test says the cable is bad, replacing the cable fixes it; Samsung says no service is needed.

Some TVs have a setting that turns the screen off on purpose. The Sharp manual describes a Sound only menu (Suara saja on its Indonesian menu): while you listen to a music program, the screen can be turned off so only the audio plays. If this setting is on, you get exactly the symptom in question: sound with no picture on the screen. Sharp's troubleshooting table lists this setting as one of the things to check when there is no picture.

According to Sharp, Sound only switches back off when you do something that changes the picture, such as changing the input source. So pressing INPUT is often enough to bring the picture back.

Check the picture settings as well. Sharp asks you to make sure the picture settings are correct when there is no picture. On a Sharp Google TV, the Picture menu holds the Backlight and Brightness settings; make sure neither is at its lowest position. Menu names and positions differ between brands and models, so match them against your TV's manual.

The Sharp manual says that outside influences such as lightning and static electricity can make the TV work improperly. The recommended fix: turn off the TV's power or unplug its power cable, then reconnect it after 1 or 2 minutes.

This matters in the Indonesian rainy season, when lightning and power outages often come together. If the picture disappears after an event like that, try this power reset once before you conclude that something is broken. Pull the plug by holding the plug head, not the cable, and make sure your hands are dry.

If the TV will not be used for a long time, for example while you are away for mudik, the holiday trip home, Sharp suggests unplugging its power cable from the outlet.

Some damage inside a TV can be prevented by placing it properly. The Sharp manual asks you not to cover or block the vents in the cabinet, and not to put the TV in an enclosed shelf without enough ventilation. Poor ventilation can cause overheating and shorten the product's life.

Sharp also forbids mounting the TV where water can drip on it, such as under an air conditioning unit or near a humidifier. It recommends a distance of at least 1 meter from the air conditioner outlet. Water dripping into the TV can cause a fire, an electric shock or damage. In many living rooms the TV and the air conditioner hang on the same wall, so check the distance between them.

Do not put a flower vase or any container of water on the TV, and keep the TV away from heat sources such as a stove.

Contact the authorized service center for your TV's brand if:

• the TV menu does not show at all or is cut off by the black area, while the sound keeps playing;
• the screen stays black with every device, cable and input port you have tried;
• the black screen appeared after lightning and does not recover with a power reset;
• water has dripped into the TV, you smell burning, or the TV turns itself off.

On an LED TV, the picture needs a backlight behind the panel, powered by the power supply board. If either fails, the screen goes dark while the sound keeps playing. Opening the back cover, replacing the backlight or the power supply board, replacing a capacitor, and draining a capacitor are jobs for a technician. The capacitors on the power supply board keep a charge after the plug is pulled. Tell the service center the result of the menu test and the steps you have tried.