Panasonic TH-47LF20E Operating Guide
43
Troubleshooting
Before you call for service, determine the symptoms and make a few simple checks as shown below.
Symptoms
Checks
Picture
Sound
Interference
Noisy Sound
Electrical Appliances
Cars / Motorcycles
Fluorescent light
Cars / Motorcycles
Fluorescent light
Normal Picture
No Sound
Volume
(Check whether the mute function has been activated on the remote control.)
(Check whether the mute function has been activated on the remote control.)
No Picture
No Sound
Not plugged into AC outlet
Not switched on
Picture and Brightness/Volume setting
(Check by pressing the power switch or stand-by button on the remote control.)
Not switched on
Picture and Brightness/Volume setting
(Check by pressing the power switch or stand-by button on the remote control.)
No Picture
Normal Sound
If a signal with a non-applicable colour system format, or frequency is input, only
the input terminal indication is displayed.
the input terminal indication is displayed.
No Colour
Normal Sound
Colour controls set at minimum level
(see page 24, 25)
Colour system (see page 38)
(see page 24, 25)
Colour system (see page 38)
No remote control operations can be performed.
Check whether the batteries have discharged completely and, if they have not,
whether they were inserted properly.
Check whether the remote control sensor is exposed to an outdoor light or a
strong fl uorescent light.
Check whether the remote control designed specifi cally for use with the unit is
being used. (The unit cannot be operated by any other remote control.)
whether they were inserted properly.
Check whether the remote control sensor is exposed to an outdoor light or a
strong fl uorescent light.
Check whether the remote control designed specifi cally for use with the unit is
being used. (The unit cannot be operated by any other remote control.)
A cracking sound is sometimes heard from the unit.
If there is nothing wrong with the picture or sound, this is the sound of the cabinet
undergoing very slight contractions in response to changes in the room temperature.
There are no adverse effects on the performance or other aspects.
undergoing very slight contractions in response to changes in the room temperature.
There are no adverse effects on the performance or other aspects.
The top or bottom of the picture on the screen is cut
off when I use the zoom function.
off when I use the zoom function.
Adjust the position of the picture on the screen.
Areas at the top and bottom of the screen where
the image is missing appear when I use the zoom
function.
the image is missing appear when I use the zoom
function.
When using a video software program (such as a cinema size program) with a
screen wider than one in the 16:9 mode, blank areas separate from the images
are formed at the top and bottom of the screen.
screen wider than one in the 16:9 mode, blank areas separate from the images
are formed at the top and bottom of the screen.
I can hear sounds coming from inside the unit.
When the power is turned on, a sound of the display panel being driven may be
heard: This is normal and not indicative of malfunctioning.
heard: This is normal and not indicative of malfunctioning.
Parts of the unit become hot.
Even when the temperature of parts of the front, top and rear panels has risen,
these temperature rises will not pose any problems in terms of performance or
quality.
these temperature rises will not pose any problems in terms of performance or
quality.
Power automatically turns off unexpectedly.
Check the settings of “Power management” and “Auto power off” in the Setup menu.
Any of them may be set to “On”. (see page 31)
Any of them may be set to “On”. (see page 31)
This LCD Display uses special image processing. Hence a slight time lag may occur between image and audio, depending on the type
of input signal. However, this is not a malfunction.
of input signal. However, this is not a malfunction.
LCD Display panel
Symptoms
Check
The screen darkens slightly
when bright pictures with minimal
movements are shown.
when bright pictures with minimal
movements are shown.
The screen will darken slightly when photos, still images of a computer or other pictures with minimal
movements are shown for an extended period. This is done to reduce image retention on the screen
and the shortening of the screen’s service life: It is normal and not indicative of malfunctioning.
movements are shown for an extended period. This is done to reduce image retention on the screen
and the shortening of the screen’s service life: It is normal and not indicative of malfunctioning.
It takes a while for the picture
to appear.
to appear.
The unit digitally processes the various signals in order to reproduce esthetically pleasing images. As
such, it sometimes takes a few moments for the picture to appear when the power has been turned
on, when the input has been switched.
such, it sometimes takes a few moments for the picture to appear when the power has been turned
on, when the input has been switched.
The edges of the images fl icker.
Due to the characteristics of the system used to drive the panel, the edges may appear to fl icker in
the fast-moving parts of the images: This is normal and not indicative of malfunctioning.
the fast-moving parts of the images: This is normal and not indicative of malfunctioning.
There may be red spots, blue
spots, green spots and black
spots on the screen.
spots, green spots and black
spots on the screen.
This is a characteristic of liquid crystal panels and is not a problem. The liquid crystal panel is built
with very high precision technology giving you fi ne picture details. Occasionally, a few non-active
pixels may appear on the screen as fi xed points of red, blue, green, or black. Please note this does
not affect the performance of your LCD.
with very high precision technology giving you fi ne picture details. Occasionally, a few non-active
pixels may appear on the screen as fi xed points of red, blue, green, or black. Please note this does
not affect the performance of your LCD.
Image retention appears
Image retention may occur. If you display a still picture for an extended period, the image might remain
on the screen. However, it will disappear after a while. This is not considered as malfunction.
on the screen. However, it will disappear after a while. This is not considered as malfunction.