Toshiba 47HL167 Service Manual page 15

*** Warranty Concession
required for LCD panel
replacement. Digital photo
may be requested.
Contact Technical
Support.
the back light
supply source present
NO
shortly after the power
switch is pressed?
(24V-Pins 1-5
CN804)
Suspect the
back light
supply source.
Suspect
System
Control or
Low-B supply
problems.
NO
Does the back light
function and then turn
off?
Is
YES
Is the back
light switching
NO
signal (3VDC Pin 1-
CN61) present shortly
after the power switch
is pressed?
NO
Suspect the
CCFL inverter.
Does
the screen light
NO
unevenly? (Normal
screen with a shaded
area)
YES
If it is available , try the
CCFL inverter. If this does
not help, replace the LCD
display. ***
YES
Using
a scope or frequency
counter, is the CCFL
inverter operating?
14
YES
defective CCFL
(Lamp). The
display should
be replaced.
Operation of the inverter can
be determined by placing a
scope probe or frequency
counter test lead NEAR the
inverter. If the inverter is
operating, the operating
frequency (40 to 70 Khz) or
waveform pictured below will
be displayed.
Do not connect the
test leads directly to
the inverter!
YES
This
normally
indicates a
***