Fixing them and knowing/understanding them are two completely different things. Just like a car a mechanic could fix something but not necessarily tell you about performance, fuel economy or all of its features.
The Myths and Facts about Plasma and LCD TVs
When it comes to plasma or LCD TVs there are hundreds of sites, sales people, friends and colleagues who will often tell you which technology and type of tv is the one to get. You will have no doubt heard stories of the death of one technology followed by the same technology being stated as the ultimate in tv picture quality. The fact is that more often than not most of these stories arise due to several reasons. Firstly the sales person in the shop often receives extra bonuses for selling a particular brand. Secondly, some people are just die hard technology geeks who won't ever believe that the other technology is better. Finally the other main reason is, if you had just bought a £600 LCD TV you are hardly going to ever admit that a plasma TV is better. So let's start listing a few of the myths and facts on plasma and LCD tvs.
Myths
Plasma screens suffer from burn-ins and LCDs aren't susceptible to burn-in. Although in the late 90's when Plasmas first arrived on the consumer market, there were issues with burn-ins, these issues have been addressed by the tv manufacturers and most modern plasmas from reputable manufacturers do not suffer from this problem anymore and although it is always more of a possibility that burn-in can happen on a plasma or LCD TV compared to CRT TVs, it is by no means a reason to not buy a plasma. Out of interest we have actually only witnessed burn-in on two occasions, and both were on LCDs. One being on an LG LCD, when the colour bars were left on screen for only a few hours. The second was on an LCD computer monitor but this often happens when using computers as the image displayed on screen is more constant than a tv picture.
LCD TVs have better viewing angles than Plasmas. The truth is that there is not much in it. If you want to be really technical then in reality Plasmas often acheive slightly better viewing angles. Again, though, the difference is minimal and is not a good enough reason to not consider LCDs. Besides I don't want to be watching TV at 178 degrees to the TV.....I want to be sitting in front of it!
Both LCD and Plasma TVs provide better picture quality than old CRT TVs. Definitely not true if you are watching normal Pal resolution TV (i.e. Freeview, Terrestrial, normal Sky digital or Virginmedia). You'll only get a better picture quality on a plasma or LCD if you are watching HD content, and that is more to do with the fact that the image was captured in HD in the first place rather than the TV technology.
LCDs now make TVs that show better blacks than Plasmas. This is one of the most frustrating statements. Mainly because although LCDs have really improved their contrast ratios and in some occasions matched the levels of blacks to a plasma, the method of measuring contrast ratios is a very dubious one and there is no law stopping tv manufacturers from exploiting this. To put it bluntly, if you ever see a TV claiming that is has over 20,000:1 contrast ratio then just beware that it is probably not going to give you any better a contrast ratio than one that says 10,000:1. The reason is that manufacturers can firstly state 'Dynamic' contrast ratios which is basically what contrast is possible in extreme pictures. This is not much use as you will want to know what is your typical contrast. Secondly, some tvs can outrageously use the level of black when the TV is off as a point of reference for working out the contrast ratio.
Facts
Plasmas do produce better blacks than LCDs no matter what contrast ratio is stated on the TV. As mentioned on our homepage (and see further explanation on the two technologies below) LCDs have to block out the light that is always on at the back of an LCD screen, while a Plasma does not have this problem and can just stop the electicity from making one or more pixels from illuminating.
HD CRTs still obtain the best picture quality for HD. The only problem here is that is they aren't made for the consumer so you have no choice. They are also very expensive to make. They are often used in the television industry and can cost around £15,000-£20,000. Samsung did make one for around £600 a couple of years ago but it never took off, as part of the attraction of plasma or LCD tvs are that they are flat, sleak and look cool. They are also now improving all the time and if you ever get the chance to buy the Pioneer Kuro 50" or more Plasma TV, believe me you won't be disappointed.....although you might be by the £3000+ price tag on it.
Both Plasmas and LCDs are inherently progressive. If you read our 'Buying Guide' you would have read about how CRT tvs display an image. Well, images are not displayed this way in either plasma or LCD tvs. They don't show one field of alternate lines in half a frame and then the other field in the second half of the frame. They are all displayed at the same time, just like when a light is shone through the film in a projector at the cinema.
LCD (Liquid Crystal Display)
As the names suggests, LCDs contain liquid crystals. To summarise, each pixel in the tv contains two polarised filters and two electrodes. Between these electrodes is the liquid crystal. Normally if there was no crystal, then light would not pass through the perpendicular polarised filters. When there are crystals and a voltage is applied, then the crystal molecules change their structure and refract the light in such a way that allow varying amounts of light through the two polarised filters. When a very large voltage is applied, the molecules are arranged in such a way that the crystal does not refract the light and the light is thus blocked by the two perpendicular filters only, causing the pixel to look black. The light source comes from a back light that is always on when the tv is on.
Plasma
This time each pixel is made up of a chamber full of two inert gases, Neon and Xenon. One end of these chambers is connected to an electrical source and when a voltage is applied to the chamber, the gas turns into an ionised gas or 'plasma' which then excites phosphors at the other end of the chamber to produce light. If no voltage is applied to the chamber then no light is produced and the pixel is black. This is the main reason why plasmas produce better blacks. Think of it like this.....what is more likely to produce a better black, a tv where light is having to be blocked (by filters) or a tv where there is no light to block in the first place?
Source:
http://plasmaorlcd.co.uk/default.aspx
