TV or AC remote not working: batteries, IR sensor and the phone camera test

Samsung names the three most common reasons a TV remote stops working: problems with the batteries, pairing problems on a smart remote, or infrared sensor problems. The troubleshooting table in the Sharp TV manual adds two things that are often missed: using the remote under strong lighting, and a fluorescent lamp shining on the remote sensor on the TV.

Most ordinary TV and air conditioner remotes work by sending infrared light to a small sensor on the front of the TV or the indoor unit. This light is invisible to the eye, but it shows up on a camera. That divides the checks into two questions: is the remote still sending a signal, and is that signal reaching the sensor?

Samsung gives a quick test for TVs: press the power button while pointing the remote at the TV, then watch the indicator light on the TV. If that light does not blink, the remote's batteries do not have enough power.

1. Open the battery cover and check the polarity. Sharp and Modena both say to line up the positive and negative ends with the marks in the battery compartment.
2. If the batteries are in correctly but the remote still does not work, replace them with new ones. Samsung recommends replacing both batteries at once, not just one.
3. Use the size written in the manual. The Sharp TV remote and the Modena air conditioner remote in this example both use AAA batteries; Modena writes AAA 1.5 V.
4. Close the compartment until it clicks.

Sharp also says not to expose the batteries to excessive heat such as sunlight or fire. If the remote often lies near a window in the midday sun, or on top of a warm TV, move it somewhere shaded.

A digital camera, including the camera on a phone, can pick up infrared light that the eye cannot see. Samsung's steps:

1. Turn on the phone camera.
2. Point the front end of the remote at the camera lens.
3. Press and hold the power button on the remote while you watch the phone screen.
4. If the remote works, a light or beam from the end of the remote shows on the screen.

According to Samsung, if no light appears even though the batteries have been replaced, the problem is the remote. If a light does appear, the remote is still sending a signal, and the next checks are obstacles, the room lighting, or the sensor on the device.

This test also helps with a remote where only some buttons fail. Press each problem button one at a time while watching the phone screen. A button that shows no light is probably worn or dirty inside. Test with another phone if the result is unclear.

The infrared signal has to reach the sensor without being blocked. Samsung asks you to move any obstacle between the remote and the TV. Decorations, extra speakers, a set-top box or a photo frame placed in front of the TV can cover the sensor without you noticing.

Samsung also writes that electronic equipment around the TV, such as lamps, radios or mobile devices, can interfere with the remote signal, and suggests moving them away from the TV. The Sharp manual lists strong lighting and a fluorescent lamp shining on the remote sensor as reasons the remote cannot be operated.

Many living rooms use long fluorescent tubes or lamps aimed toward the TV. To test this, switch that light off for a moment, close the curtains if the sun hits the screen directly, then try the remote again. If the remote works again, change the angle or position of the light.

Smart TVs often come with a smart remote that connects to the TV through pairing, not only through infrared. According to Samsung, a remote like this may need to be paired again before it works properly.

On a Samsung smart remote, press the Return and Play/Pause buttons together for more than 3 seconds until the pairing window appears on the TV screen. Do this close to the TV. This method is specific to Samsung remotes; smart remotes from other brands have their own button combination, written in the TV manual.

If the smart remote still will not connect after pairing again, check its batteries the same way as an ordinary remote.

Check an air conditioner remote in the same order: polarity and batteries, the camera test, then obstacles in front of the indoor unit. The camera test works the same way as on a TV remote; if a light shows on the phone screen when you press a button, the remote is still sending a signal.

You can still switch the air conditioner on while the remote is out of action. The Modena split air conditioner manual describes an emergency on/off button on the indoor unit, used when the remote is broken or lost. Press it once and the air conditioner runs with its default settings. Press and hold it for 5 seconds and it runs in cooling mode with the fan on high. Other settings such as the temperature still need the remote.

The position and behavior of the emergency button differ between brands and models, so look it up in your air conditioner's manual.

The result of the camera test decides the last step:

• If the camera picks up no light with new batteries inserted correctly, the remote is at fault. Ask the brand's authorized service center for a replacement remote that matches the TV or air conditioner model.
• The camera may pick up light, with nothing blocking the path and the room lights ruled out. If the TV or air conditioner still does not respond, have an authorized service center check the sensor on the device.
• If the remote still does not work after all the steps above, Samsung suggests contacting the Samsung Service Center for a Samsung TV; other brands have their own service.

In the meantime, use the buttons on the device. The Sharp TV in this example can be switched on with the POWER button and its source chosen with the INPUT button on the TV. The air conditioner can run from the emergency button on the indoor unit. Do not open the TV or air conditioner to check the sensor yourself.