HP Notebook PCs and Tablets - Learning about LCD panel defects and terminology
Review definitions of industry standard terminology related to the various cosmetic conditions of liquid crystal display (LCD) panels.
Clean the LCD panel
Clean the liquid crystal display (LCD) panel when smudges or scratches accumulate on the display.
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Turn off the computer, and then disconnect any cables.
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Wipe the screen with a non-abrasive, lint-free cloth to remove any dust or dry particles.
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Use a computer monitor specific cleaner from a computer store to lightly dampen a lint-free cloth.
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Clean the screen, applying a moderate amount of pressure.
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Allow the LCD screen to dry completely (approximately 10 minutes).
Learn about LCD panel quality
HP and Compaq notebook liquid crystal displays (LCDs) adhere to strict quality and reliability specifications. A small percentage of LCD panels might have minor cosmetic manufacturing anomalies or irregularities such as bright or dark dots in the viewable area. These cosmetic imperfections are common to all LCD panel types and are not specific to any HP model or product line.
LCD terms and definitions
Review common terms and conditions related to LCDs (liquid crystal displays) on computers.
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Pixel: Picture element. A pixel consists of one red (R), one green (G), and one blue (B) sub-pixel, each of which are commonly referred to as dots.
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Dot: Elements that make up a pixel. Dots are one of three colors; R, G, or B. Sub-pixel transistor or dot failures might appear in several different ways.
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Always On: Bright dot on a dark background.
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Always Off: Dark dot on a bright background.
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Spot: A spot generally refers to an optical distortion due to foreign material contamination inside the cell. Spots are usually seen as small irregular dark areas.
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Lines: Lines appearing in the display pattern of the LCD. Lines might appear dark or bright and might be displayed in a horizontal or vertical position.
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Polarizer dent: Physical damage to the Polarizer which does not damage the glass. Dents might be observed when the LCD is illuminated and might appear as ghosted white lines or with dark display patterns. Polarizer dents are most likely to appear as pockmarks caused by a strike to the display.
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Polarizer bubble: Tiny air pockets behind the Polarizer.
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Polarizer scratch: Physical damage to the Polarizer that does not damage the glass.
LCD replacement criteria
Review the set of criteria HP uses when damaged liquid crystal displays (LCDs) are submitted for warranty coverage.
The number of pixels supported by a specific display type might vary. To identify the number of pixels supported by your display, multiply the native display resolution. For example, a 1680 × 1050 resolution has 1.764M pixels, which is less than 2.1M pixels and more than 1.6M pixels.
Note:
HP recommends examining any LCD panel defects at the highest possible resolution using both the brightest and darkest possible backgrounds because some sub-pixel failures might not be visible under certain conditions.
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720p, HD, SD, SD+, SVGA, VGA, WSVGA, WXGA, and XGA Panels, <1.05M pixels
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6 or more dots in any combination and any color that are always on or off
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Any 2 dots within 25mm of each other that are always on
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Any 2 dots within 15mm of each other that are always off
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HD+, SXGA+ and WXGA+ Panels, <1.6M pixels
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7 or more dots in any combination and any color that are always on or off
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Any 2 dots within 25mm of each other that are always on
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Any 2 dots within 15mm of each other that are always off
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FHD, UXGA, and WSXGA+ Panels, <2.1M pixels
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8 or more dots in any combination and any color that are always on or off
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Any 2 dots within 25mm of each other that are always on
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WUXGA Panels, >=2.1M pixels
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9 or more dots in any combination and any color that are always on or off
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Any 2 dots within 25mm of each other that are always on
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Any 2 dots within 15mm of each other that are always off
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