Unique Main Video Board (A-Board) Or Lvds Cable Effects - Sony KDL-55EX500 Troubleshooting Manual

The aspect ratio can be easily changed using the "WIDE" key on the
remote controller. If the distortion follows the video then the A-Board is
causing the distortion. If the distortion remains stationary after changing
the aspect ratio then the LCD Panel assembly is causing the distortion.
WIDE Mode
Button

Unique Main Video Board (A-Board) or LVDS Cable Effects

A video distortion that has soft edges and/or is moving through the video
is most likely caused by a defect in the video processing circuitry. All video
processing circuitry is located on the A-Board. Therefore, replace the A-
Board if the video distortion has soft edges and/or is moving through the
video on the screen. Macro-Blocking (digital picture breakup) is a good
example of this type of distortion. Be careful though, macro-blocking can
also be caused by a weak RF signal when the TV is in the tuner mode.
• Poor Picture Detail - Loss of overall picture detail. A loss
of information on the LVDS lines from IC400 will cause poor
overall picture detail.
• Abnormal Picture Size or Geometry- The video signal scaler
circuit is located on the main video board A-Board. Therefore,
if either the picture size or geometry is abnormal the A-Board
is defective. Only the A-Board can cause such a distortion.
CTV-65
WIDE Mode
Function
• Color Distortion - A color distortion can be caused by a
defective IC400 or LVDS cable. The individual color signals
are spread out over the LVDS twist pair wires. For example,
the Red signal may be broken up into three components and
sent over three different LVDS twisted pairs. Therefore, this
distortion will display as a poor reproduction of a particular
color not an overall loss of one color. Use a Red, Green, and
Blue raster generator to confirm a poor reproduction of a
single color.
• Loss of a Single Color - A loss of a single color can only be
caused by a defective MT5388 (IC400). Use a Red, Green,
and Blue raster generator to confirm a complete loss of a
single color.
• RF Signal Distortion - A weak video signal from the antenna
or cable connection can cause RF video distortions. The signal
strength of the Digital Signals can be checked in the USER
menu. Go to the Product Support and Signal Diagnostic item to
check signal strength and errors. NOTE: This is only for digital
channels. No information will display for analog channels. The
SNR should be in the range of 25db to 30db and there should
be zero Errors.
Product Support
Signal Diagnostics
Screen
AZ1K Chassis Models Overview
Signal Diagnostics
26