Magnavox digital tuners are digital-to-analog converters that are used to pick up digital signals that are broadcast over the air by local television stations. A digital-to-analog converter is a set-top box TV tuner that receives digital signals via a TV antenna and converts them into analog signals so that televisions that were made prior to 2009 can display free over-the-air broadcast television stations. Signs that your Magnavox tuner is having a problem with a signal may be loss of picture, static, no sound, freezing picture, intermittent audio or a black screen that says "no signal."
If you aren't receiving a picture or aren't picking up a signal on a TV that is hooked up to a Magnavox tuner, it could be that you have accidentally activated the analog tuner setting on your TV. When this happens, the TV's antenna searches for an analog signal that it cannot find, as they are no longer being broadcast by TV stations. This can be remedied by changing the setting of your TV back to the digital tuner. Also check to ensure that the Magnavox tuner is set to digital and not analog pass-through.
If your Magnavox tuner picked up TV channels but no longer receives a signal, you will have to rescan for digital television or DTV channels. TV stations can change their digital frequencies over time, so you may have to scan to find them. If you have no signal or picture, or your TV has white snow on the screen accompanied by a hissing static sound, it means that the channel that your TV is on has changed from Channel 3 to another channel. Change your TV channel back to 3 to see if this solves the problem. If Channel 3 doesn't work, change your TV channel to 4 and try that instead.
You may have the wrong type of antenna for a Magnavox tuner. Most DTV tuners work best with TV antennas that are a combination of VHF and UHF receivers, such as an HDTV antenna. Combination antennas with both VHF and UHF receivers pick up a wider range of digital broadcast frequencies. This is because VHF signals are used to broadcast digital Channels 2 through 13 and UHF signals are used to broadcast digital Channels 14 through 51. You may be able to pick up a signal by upgrading your TV antenna to a combination antenna or using an outdoor antenna to pick up DTV signals.
Depending on where you live, you may not be able to receive a signal from certain DTV stations. Some DTV stations may be transmitted on a signal that is too weak to reach your home. When the signal strength is low, the TV picture and sound may disappear. Signs of a TV station with a low signal strength are channels that appear distorted or have static. If you use a splitter to connect one antenna to multiple Magnavox tuners in your home, the splitter can weaken the signal even more and you won't be able to pick up the TV channel at all. Remove the splitter to see if your reception improves, as this may be the problem.