Questi sono alcuni strumenti di uso comune usati per lavorare su questo dispositivo. Potrebbe non essere necessario ogni strumento per ogni procedura.
Background and Identification
Television (TV) is a telecommunication medium used for transmitting moving images in monochrome (black and white), or in color, and in two or three dimensions. The term ‘television’ can refer to a television set, a television show, or the medium of television transmission. Television is used as a mass medium for advertising, entertainment, news, and sports.
In 2013, 79% of the world’s households owned a television set. Beginning in the late 1990s, bulky, high-voltage cathode ray tube (CRT) screen displays were replaced with compact, energy-efficient flat-panel televisions with liquid-crystal displays (LCDs, both fluorescent-backlit and LED), organic light-emitting diode (OLED) displays, and plasma displays in a hardware revolution. Most television sets sold in the 2000s were flat-panel and mainly light-emitting diode (LED) display. By the mid-2010s, major manufacturers announced the discontinuation of CRT, DLP, plasma, and fluorescent-backlit LCDs. OLED displays were gradually replacing LED displays in the 2020s, and many manufacturers have announced that they will increasingly produce smart TVs with integrated Internet and Web 2.0 functions.
Television signals were originally distributed only as terrestrial television using high-powered radio-frequency transmitters. These transmitters broadcast the signal to individual television receivers. Television signals have also been distributed by coaxial cable or optical fiber, satellite systems, and via the Internet. Until the early 2000s, television signals were transmitted as analog signals, but a transition to digital television was completed in the late 2010s.
A standard television set includes multiple internal electronic circuits, including a tuner for receiving and decoding broadcast signals. A visual display device that lacks a tuner is generally referred to as a ‘television,’ but is correctly called a video monitor.
History and Development
The television was invented in the early 20th century as a novel way to transmit moving pictures through radio waves. Early television sets actually used mechanical means to etch out a picture from a signal using a Nipkow Disk, with the first demonstration taking place in Paris in 1909. This early “television” technology was capable of transmitting an 8x8 pixel image, with the first demonstration showing individual letters of the alphabet, and clearly!
In 1911, Rosing and Zworykin invented a method of passing an image over a mechanical mirror drum to transmit the image via wire to a “Braun tube,” now known as the Cathode Ray Tube, or CRT. Then in 1921, Edouard Belin transmitted the first image over radio waves using his belinograph. The early 1920s saw the birth of the first true televisions, adding amplification to these two technologies to send moving images with some semblance of clarity over air and wire. By 1928, the Baird Television Company sent the first transatlantic broadcast from London to New York, starring Baird’s own ventriloquist puppets “James” and “Spooky Bill,” whose painted faces showed up in higher resolution than their human operator due to their increased contrast.
Parallel to all this, advancement in the transmission of images through electrical means was happening in the scientific community, advancing early experiments in deflecting cathode rays by physicist J.J. Thompson and the invention of the “Braun tube” by Ferdinand Braun in 1897. By 1926, Hungarian engineer Kálmán Tihanyi had invented a television set that both scanned and displayed images using electrical means, with Farnsworth’s image dissector transmitting the first electronic image the following year in 1927.
Eventually, the analog transmissions became surpassed in quality to digital transmissions, seeing more efficient use of bandwidth, bringing about the more modern televisions we see today. Now televisions use the latest in LCD and OLED technology, with new methods like progressive scanning and curved screens being used to produce images sometimes indistinguishable from reality. With these new technologies, the scope of the hardware used has changed in turn, with most televisions sporting similar processors to computers on motherboards dedicated to integrated smart technologies. While working on your old CRT may be ill-advised, this page should help if you’re in the need of some TV repair information.
The TV turns on but shows a blue, green, or black screen
A television showing a blue, green, or black screen is most likely caused by a lack of signal. Make sure that your satellite or cable box is powered on and the television is set to the correct output by pressing ‘Input’ —> ‘Source’ —> ‘TV/Video’ on your remote control. Press the button to cycle through the input options until your TV gets a picture back. Also, be sure to check behind the TV for loose connections, and re-plug anything that is not connected properly. If your television is still not receiving a signal, reset the cable box by unplugging it and plugging it back in. There may be an issue with your signal or the box itself, so try switching the connections to another device. If the picture works with another device, contact your provider for service for the box itself.
Video not matching audio
If you are seeing an actor’s mouth move but are not hearing the audio in sync, go into your television’s or cable box’s audio settings and adjust the “audio delay” to get the video and audio back in sync.
Hearing an echo
If you are hearing an echo with your television’s audio system, you most likely have a separate sound system like a soundbar or surround sound system and the volume is playing through both the external sound system and your TV’s speakers. Disable or mute the audio for your TV speakers and use only your external sound system, which is likely much higher quality than the TV’s built-in speakers.
The picture is pixelating or breaking up
If your television picture is cutting out, breaking up, or pixelating (looks like the picture is made up of many squares), the television is probably experiencing a weak signal. Ensure that all connections are tight by checking all of the connections from the wall to your cable box and from the cable box to the television. If you continue to experience pixelation problems, you may need to contact your cable or satellite provider.
The picture is squashed, stretched, or cropped
If the television’s picture is squashed, stretched, or cropped, something is most likely wrong with the picture size settings (zoom, wide, aspect ratio, or picture). In many cases, the best setting is ‘Direct’ or ‘Just-Fit,’ which instructs the TV to show the video as it receives the signal. If you are using a DVD player or an old gaming system connected to the television, set the video to 4:3 (otherwise, the television will stretch the picture to the modern 16:9 ratio). If you are using a computer connected to the television, turn off Overscan to avoid strange cropping.
Flatscreen Plasma, LED, OLED, or QLED has lines or is cracked
If the television screen has lines, pull up the TV menu. If the lines run through the menu, or if the screen is cracked, the television’s panel needs to be replaced.
TV will turn on from the remote but not the cable or satellite box
If the television will turn on from the remote but not from the cable box or satellite box, the box is not communicating with the TV properly. Try turning the box off and unplug it for at least 15 seconds and turning it back on again.
Cable or satellite receiver is frozen
If your cable or satellite has frozen, it has most likely crashed like any other computer can. Try turning it off, unplugging it, waiting 15 seconds, and then turning it back on again to reboot the receiver. Crashes are often caused by overheating, so make sure not to cover the heat vents on the receiver.