Sony KDL32EX308, KDL22EX308 manual Video Distortion, No Video Troubleshooting Flowchart, CTV-68

Chapter 3 - Troubleshooting

No Video

Backlights		No	TCON
turned on ?			(LCD Panel)
	Yes
Any OSD		Yes	BAL Board
graphics
present ?
	No
Unplug LVDS
connector at			Any flashes
TCON while unit					No	TCON
is running . This			seen on
						(LCD Panel)
may need to be			screen?
done more than
once				Yes
			BAL Board

Video Distortion

This is, perhaps, the more difficult failure to diagnose. It is difficult when talking to the customer on the phone because an accurate description of the problem must be obtained in order to determine which part (or parts) to bring to the location. It may also be difficult for the technician when the problem is witnessed.

If the problem is specific to one or more inputs it should be easy to determine if the fault lies on the BAL board or a device that is plugged into it. If the distortion occurs at all inputs it must be analyzed based on what appears on the display and isolated to the BAL board, TCON, or LCD panel. These components usually cause distortions that are unique to the specific circuit. Below is an example of the typical distortions:

BAL Board: Since the video signal is processed on a frame-by-frame basis it is very unlikely that a distortion that is occurring on a specific part of the display panel is originating here. Distortion problems originating in the video process circuits tend to affect the entire picture. Listed below are some examples:

•Improper color reproduction or no color

•Improper luminance levels

•Lack of detail in the picture

•Distortions that change with movement in the video

•Diagonal lines

•No video

FIGURE 3-2

NO VIDEO TROUBLESHOOTING FLOWCHART

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