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| Thread ID: 46440 | 2004-06-23 22:52:00 | Life of LCD vs CRT Screens | Steve_L (763) | Press F1 |
| Post ID | Timestamp | Content | User | ||
| 247212 | 2004-06-27 23:07:00 | Philips LCD with zero bright dot warranty here (www.ascent.co.nz). But looks like it only protects against "bright" pixels, I wonder if it also covers "dark" pixels. Best to try before you buy. Mind you I'm a good one to say that considering I bought mine online, but then I was quite prepared to send it back if I wasn't happy. | Sb0h (3744) | ||
| 247213 | 2004-06-28 09:22:00 | I rang Philips today and found that they have a Zero Bright Dot warranty. Black pixels will not be covered. In any case I plan to have the retailer turn the LCD screen on so I can see if there are any bad pixels, or if Noel Leemings can order the same or similar screen I'll go with their right of return - and Fly Buys :) . They emailed me the following, which seems fairly good to me: Philips' Flat Panel Monitors Pixel Defect Policy Philips strives to deliver the highest quality products. We use some of the industry's most advanced manufacturing processes and practice stringent quality control. However, pixel or sub pixel defects on the TFT LCD panels used in flat panel monitors are sometimes unavoidable. No manufacturer can guarantee that all panels will be free from pixel defects, but Philips guarantees that any monitor with an unacceptable number of defects will be repaired or replaced under warranty. This notice explains the different types of pixel defects and defines acceptable defect levels for each type. In order to qualify for repair or replacement under warranty, the number of pixel defects on a TFT LCD panel must exceed these acceptable levels. For example, no more than 0.0004% of the sub pixels on a 15" XGA monitor may be defective. Furthermore, Philips sets even higher quality standards for certain types or combinations of pixel defects that are more noticeable than others. This policy is valid worldwide. Pixels and Sub pixels A pixel, or picture element, is composed of three sub pixels in the primary colors of red, green and blue. Many pixels together form an image. When all sub pixels of a pixel are lit, the three colored sub pixels together appear as a single white pixel. When all are dark, the three colored sub pixels together appear as a single black pixel. Other combinations of lit and dark sub pixels appear as single pixels of other colors. Types of Pixel Defects Pixel and sub pixel defects appear on the screen in different ways. There are two categories of pixel defects and several types of sub pixel defects within each category. Bright Dot Defects Bright dot defects appear as pixels or sub pixels that are always lit or 'on'. Black Dot Defects Black dot defects appear as pixels or sub pixels that are always dark or 'off'. Pixel Defect Tolerances In order to qualify for repair or replacement due to pixel defects during the warranty period, a TFT LCD panel in a Philips flat panel monitor must have pixel or sub pixel defects exceeding the tolerances listed in the following tables. |
Steve_L (763) | ||
| 247214 | 2004-06-28 09:24:00 | >>>They emailed me the following "They" meaning Philips, not Noel Leemings. - Steve |
Steve_L (763) | ||
| 247215 | 2004-06-28 09:33:00 | Thanks for that, it's nice to have an explanation from the manufacturer regarding their warranty. | Sb0h (3744) | ||
| 247216 | 2004-06-28 10:07:00 | >In order to qualify for repair or replacement due to pixel defects during the warranty period, a TFT LCD panel in a Philips flat panel monitor must have pixel or sub pixel defects exceeding the tolerances listed in the following tables. Do you have the data from the tables mentioned? |
metla (154) | ||
| 247217 | 2004-06-28 20:43:00 | Hello Metla, In the next few minutes, will email (where you work) you the html file that has the tables. Cheers, Steve |
Steve_L (763) | ||
| 247218 | 2004-06-28 20:53:00 | In summary, the Philips pixel policy is this: The "B" and "P" models of LCD screens, e.g. 170B, have ZERO tolerance to bright dots. But the cheaper "S" models can have 4 or fewer as acceptable unless the dots are adjacent where 1 or 2 are acceptable. BLACK DOTS: For all models, 4 or fewer are acceptable unless adjacent where only 1 is acceptable for B and P models, and 2 or fewer for S models. I wonder if anyone knows of the Viewsonic pixel warranty? >>This post did not seem to get through so is being sent twice. - Steve |
Steve_L (763) | ||
| 247219 | 2004-06-29 08:08:00 | From Viewsonic web site: www.viewsonic.com [ It is not as good as Philip's pixel warranty. ] LCD Pixel Criteria ViewSonic is committed to customer satisfaction by providing the highest quality products in the industry. The result is that our LCD displays generally have very few non-performing pixels. For example, an 18" SXGA (1280 x 1024) display has nearly 4 million sub-pixels. A product exhibiting 7 non-performing pixels would equate to an extremely small 0.00018 percent of the total sub-pixels. (1280 Horizontal Pixels) * (1024 Vertical Pixels) * (3 sub-pixels per pixel) = 3,932,160 sub-pixels [(7 non-performing pixels) / (3,932,160 sub-pixels)] * 100% = 0.00018% To ensure the highest performing displays, ViewSonic sets limits as to the allowable number of pixel anomalies. ViewSonic has adopted the following pixel criteria to supplement our existing three-year limited warranty. This policy applies to all ViewSonic LCD displays during the warranty period. ViewSonic sets limits on 14" - 15" LCD's at 4 bright sub-pixels, 4 dark sub-pixels, or a combination of 4. ViewSonic sets limits on 17" - 19" LCD's at 7 bright sub-pixels, 7 dark sub-pixels, or a combination of 7. ViewSonic sets limits on 20" & greater LCD's at 10 bright sub-pixels, 10 dark sub-pixels, or a combination of 10. It is possible that any replacement display may also have some non-performing sub-pixels. This should be considered when requesting a warranty exchange. |
Steve_L (763) | ||
| 247220 | 2004-06-29 08:15:00 | >>>Crikey! Wonder why the text above is all underlined? I did not add anything.... | Steve_L (763) | ||
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