Toshiba 42HL67 - 42" LCD TV - Second Level Video Troubleshooting; Video Signal and Display Issues; Power Distribution Checks for Video

Is the problem
associated with an
analog or digital
input?
Analog
Digital
Is the on screen display
normal?
NOYES
Using the
power distribution
diagram, are the
voltages normal at
CN90B and
CN91B?
NO
Suspect the
Low B
module.
YES
Suspect the
Seine (Digital)
module.
Using
the power
distribution diagram,
are the voltages normal
at P811A and
P811B?
Suspect the AV tuning module.
This can be confirmed by using the
wiring interconnect diagram and
checking the Y, Pb, Pr signals at
plug CN72A.
YES
Suspect the
Low B
module.
NO
No or distorted
video
Does
the back light function
normally when the unit
is turned on?
YES
NO
Is
the screen discolored
or does it have streaks
or dark areas with no
signal input?
NO
Replace the
LCD display
panel.
YES
Examples
11
11