Panasonic Troubleshooting, LCD Display panel

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
		Normal Picture	No Sound	Volume
				(Check whether the mute function has been activated on the remote control.)
				Not plugged into AC outlet
		No Picture	No Sound	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 format, or frequency is input, only the input terminal
				indication is displayed.
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 Àuorescent light.
				Check whether the remote control designed speci¿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.
The top or bottom of the picture on the screen is cut				Adjust the position of the picture on the screen.
off when I use the zoom function.
Areas at the top and bottom of the screen where				When using a video software program (such as a cinema size program) with a screen
the image is missing appear when I use the zoom				wider than one in the 16:9 mode, blank areas separate from the images are formed at the
function.				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.
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.
Power automatically turns off unexpectedly.				Check the settings of “No Signal power off”, “PC Power management”, “DVI-D Power
				management” and “No activity power off”. Any of them may be set to “On (Enable)”.
				(see page 31, 32)
There is no picture displayed or sound output				When HDMI or DVI signals are input to the Display using a selector or distributor, sound or
sometimes.				images may not be output in the normal fashion depending on the selector or distributor used.
				The symptoms may be improved by turning the power off and on again, or by replacing
				the selector or distributor.
The RS-232C is uncontrollable				Check whether the connection has been made properly. (see page 12) When controlling
				the RS-232C command on page 12 from the RS-232C terminal in the display, make
				sure that “Control I/F Select” is “RS-232C”. (see page 41)
The LAN is uncontrollable				Check whether the connection has been made properly. (see page 47) Check whether
				“Control I/F Select” is “LAN” when controlling with the WEB browser control or the command
				control on page 48. (see page 41) Check whether “LAN Setup” has been con¿gured properly.
				(see page 42) When connecting to a device of AMX, Crestron Electronics, Inc., set “AMX
				D.D.”, “Crestron Connected™”, according to the device to use. (see page 41)

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.

LCD Display panel

	Symptoms	Check
The screen darkens slightly when bright pictures with		The screen will darken slightly when photos, still images of a computer or other pictures with
minimal movements are shown.		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.
It takes a while for the picture 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.
The edges of the images Àicker.		Due to the characteristics of the system used to drive the panel, the edges may appear
		to Àicker in 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		This is a characteristic of liquid crystal panels and is not a problem. The liquid crystal panel
black spots on the screen.		is built with very high precision technology giving you ¿ne picture details. Occasionally,
		a few non-active pixels may appear on the screen as ¿xed points of red, blue, green, or
		black. Please note this does not affect the performance of your LCD.
		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.
Image retention appears

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