Monday, November 05, 2012

LCD TV _ FAULTS _ SYMPTOMS _ Contn:


Contn:                                                       [2]


Flashing.  Bright and dark display alternately.  Panel and VSC connect bad.



White screen.  B/L normal, only white screen display.  May be caused by surge current and EDS.



Black screen.  B/L normal, only black screen display.  May be caused by surge current and EDS.


Flicker.  Crosstalk.  LCD - Vcom imbalance.


Abnormal color.  Capacitance improper bring crosstalk inside LCD panel.


Abnormal color:  Only color abnormal.  
  1. Chip loose action.
  2. IC short or solder joint bad.
  3. Panel and VSC connect bad.
Mechanical noise.   When turn on, panel appear cacophony.  Caused by mechanical noise of back light [B/L] unit.

Ripple.  Concentric circle.  Caused between mechanism and panel.


Back Light ]B/L] off.  Loose action.  Check the connection.
Back Light [B/L] brightness darker.  Check the connection between wire and electrode.


B/L wire damaged.  Operation abnormal or noise.
No back light.
Back light shutdowns sometimes.  
Check for any loose contact between electrodes and wire to backlight lamp.

F/M in Back Light [B/L].  F/M in B/L unit.


Brightness at the bottom of LCM is brighter than normal.  Light leakage.  B/L unit bad.



B/L brightness asymmetric.  Uniformity.  Sheet in the B/L unit is uneven.



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