LG 26TS30MF Installation Manual page 25

Causes & Phenomena of the Line Defect
The line defect could occur on your set if you strike on the edge of the set.
LOG (LINE ON GLASS) DEFECT
If there has been a shock on Module Left/Top Corner, then you might see at the Left/Top
LOG Crack or Horizontal Line Defect
COF (CHIP ON FILM) DEFECT
Shock on Module Top Side  Top COF Crack
Vertical Line Defect
[ Line defect picture ]
Shock on Module Left Side  Left COF Crack
Horizontal Line Defect
[ External damage]
25