Week 24, 2003<\/p>\n
Q) My husband and I “inherited”\u009d a big screen projection TV from my in-laws. It is around eight years old and the picture looks good, but it has two problems. First, people and objects have colored fringes or shadows around them, like you are watching a 3-D movie without wearing the special glasses. Second, there is a circuit breaker on the back that we have to push a certain way to get it to work.<\/span> If we push it in all the way, the TV will shut off as soon as we turn it on.<\/span> If we push it in partway, it will stay on for a while before the TV turns off.<\/span> Any idea what is wrong, and should we have a repairman look at the TV? A) If you plan on keeping the TV, you should have an authorized service person look at it before you try using it again.<\/span> Televisions, especially rear-projection televisions, get very hot and work under very high voltage.<\/span> Electrical problems can create a shock or fire hazard, and that is why your TV has a circuit breaker.<\/span> The circuit breaker is a safety device designed to activate and cut power when it detects an electrical problem. <\/span>If it needs reset repeatedly, your television definitely needs servicing. <\/span> There is no telling how much the repair will be, but it is likely to be much less expensive than buying a brand-new projection set.<\/span> It is worth the cost of a service call to get a repair estimate and an evaluation of the TV’s condition.<\/p>\n The reason you are seeing the colored fringes is because the TV’s<\/span> picture tubes are very slightly out of alignment, commonly called convergence.<\/span> Unlike the single direct-view picture tube we commonly associate with television sets, rear projection TVs use three tubes, one for each of the three primary colors: red, green, and blue. These three tubes project three separate images that merge together on the screen to produce a full-color television picture. <\/span> The images must match up exactly for the picture to look right and the tolerance for error is very small.<\/span><\/span> When you moved the TV from your in-laws house to your home you may have knocked the tubes out of alignment a little bit<\/span>. Not to worry- except for late-model TVs with automatic convergence, all projection TVs need to have their convergence fine-tuned from time to time. <\/span>With this in mind, manufacturers make it easy for you to set the convergence yourself.<\/p>\n If you access your TV’s setup menus using the remote control, you should see a setting for convergence in the video menu.<\/span> Though there may be variations from brand to brand, generally the convergence process is the same.<\/span> When you activate convergence from the video menu, each of the separate picture tubes will project a crosshairs on the screen.<\/span> Using the buttons on the TV or the remote control, you line up these red, green, and blue crosshairs until you have a single white crosshair on your screen.<\/span> This is color theory at work; equal amounts of red, green, and blue light create white light.<\/span> When you have a single, white, non-fringed crosshair, the tubes are aligned and will produce a proper television picture.<\/p>\n I have explained this process so you can check and converge the TV yourself when the need arises.<\/span> Please do not attempt to converge your TV until you have it fixed!<\/span> I imagine when you have the TV serviced, the service agent will converge it for you, so you won’t have to use this bit of information for a while.<\/p>\n
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\n-Nicole Cox, Canonsburg, PA<\/p>\n