Dell E228WFPc, Service Manual

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22"LCD Color Monitor Dell E228WFPc
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4.5 Definition of Pixel Defects
4.5. 1.Description
These inspection standards shall be applied to LCD Module supplied by SAMSUNG LTM220M1-L01
Optoelectronics Corporation.
4.5.2 The environmental condition of inspection
viewing distance 35 ~ 50 cm
ambient illumination 300 ~ 700 Lux (normally 500 Lux)
ambient temperature 25 + - 5 'C
viewing angle
The surface of the module and the inspector's
line of view shall be at 90 degrees(TN)
90±45 (PVA)
display pattern Pure R, G, B, Black, White, Dot Gray pattern
inspection area Active area
4.5.3 Classification of defects
dark / bright spots:
points on the display which appear dark / bright and remain unchanged in size
dark / bright lines:
lines on the display which appear dark / bright and remain unchanged in size
polarizer scratch:
when the unit is lit a light, line is seen across a darker background; line does not vary in size
polarizer dent:
when the unit is lit a light, light(white) spots appear against a darker background, and do not vary in size
bright/dark dot:
a sub-pixel (R, G, B dot) stuck off / on
4.5.4 Inspection Criteria
(1) . Definition of Partial dot