Sony KDL-55BX520 Service Manual ▷ View online
KDL-55BX520 32
SECTION 5 - FLOW CHARTS AND DIAGRAMS
VIDEO INFORMATION
No Video
Backlights
turned on?
Unplug LVDS
connector at
TCON while unit
is running. This
may need to be
done more than
once
Any flashes
seen on
screen?
Yes
No
TCON
(LCD Panel)
Any OSD
graphics
present?
No
No
TCON
(LCD Panel)
Yes
Yes
Main Board
Main Board
FIGURE 5-1. NO VIDEO FLOWCHART
KDL-55BX520 33
SECTION 5 - FLOW CHARTS AND DIAGRAMS
Video Distortion
Is distortion
across entire
screen?
Any horizontal
lines?
No
No
Yes
Yes
Improper of
missing colors?
Yes
No
Vertical lines
or bars?
No
Yes
Lines move
when wide-
mode
changed?
Yes
No
TCON
(LCD Panel)
LCD Panel
Any single or
isolated vertical
lines?
Yes
LCD Panel
More than 1
vertical band?
No
Yes
TCON
(LCD Panel)
Main Board
Main Board
FIGURE 5-2. VIDEO DISTORTION FLOWCHART
KDL-55BX520 34
SECTION 5 - FLOW CHARTS AND DIAGRAMS
POWER SUPPLY INFORMATION
No Power
Is standby LED
blinking?
No
Yes
No
See protection
flowchart
Yes
Does red standby
LED on front panel
light?
Press power
button while
monitoring pin 3 of
CN6401 on power
supply board
High (3.3V)
on pin 3?
Yes
No
High (3.3V)
on pin 2?
Yes
No
Main Board
Power Board
Power Board
Power Board
FIGURE 5-3. POWER SUPPLY FLOWCHART
KDL-55BX520 35
SECTION 5 - FLOW CHARTS AND DIAGRAMS
PROTECTION INFORMATION
Protect
Shutdown.
Standby LED
Blinking
No
Yes
No
Yes
2X
3X
5X
No
Yes
LCD Panel
6X
Yes
7X
No
Immediately
After a While
Check room
temperature and
ventilation around
unit
Power Board
Main Board
“SONY” logo
appears before
shutdown?
Yes
No
LCD Panel
Power Board
Main Board
FIGURE 5-4. PROTECTION SHUTDOWN FLOWCHART
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