Hitachi 42HDT79 - UltraVision CineForm - 42" Plasma TV, Service Manual

Page: 38 / 118

37
A buzzing sound might be heard when the plasma display monitor is turned on in a very quiet
room. This is due to the plasma panel drive circuit when it is functioning. This arching sound
is normal and it is not a malfunction.
Some infrared rays are emitted from the plasma display monitor’s panel that might affect other
infrared controlling equipment.
High-precision technology is used to manufacture the plasma display panel; But in some
cases, there are minor defects in some parts of the screen. Points that do not light, points
with brightness different from that of the periphery, points with color different from that of the
periphery, etc. Some pixels will always be on or always off. Please note that this is not a
malfunction.
When receving still picture signals, (e.g. channel number indication or clock indication) for a
while, you can see image-like when the picture varied. This is not a defect.
The plasma display panel is lighting the phosphors by the discharge of internal radiation. In
some cases, this may cause the temperature of the panel surface to increase. Please note
that this is not a malfunction. The Plasma TV surface temperature is higher than a
Cathode-ray-tube.
The plasma panel is made from glass. Heavy shock on the front panel might damage it.
When the PDP monitor is transported horizontally, the glass panel has the possibility of being
broken or increasing the picture defects. At the time of transportation, horizontal style is
prohibited. More-over, please treat the plasma panel with great care because of a precision
apparatus. Please instruct transporters so that it should be put into the packing box at the time
of shipment.(There is a possibility that breakage of the panel or defects will increase.)
Rough transportation might cause damage to the panel and pixel failure.
The plasma monitor illuminates phosphor to display images. The phosphor has a finite
illumination life. After extended periods of illumination, the brightness of the phosphor will be
degraded to such extent that stationary images would burn-in that part of the screen as
grayed-out images.
Tips to prevent such image retention are:
- Do not display images having sharp brightness differences or hi-contrast images, such as
monochrome characters and graphic patterns, for long.
- Do not leave stationary images appearing for long, but try to refresh them at appropriate
intervals of time, or try to move them using screen saver function.
- Turn down the contrast and brightness controls.
PDP television has luminosity and low contrast compared with CRT television.
When a screen is seen at point-blank range, a random fine grain may be visible to a dark part.
If an apparatus (VCR, etc.) antenna line is arranged near the monitor, the image may shake,
or disturbance may be received.
There is some time lag betweeen the picture and the sound. You can see lip motion that is
delayed compared to the sound.
Electric discharge/luminescence characteristic of the PDP panel also changes with peripheral
temperature. Moreover, since there is also high power consumption value, a specified
temperature environment is required.
Storing the plasma television for a period of more than 2 to 3 months without use might cause
an unstable picture when the set is turned on.
Operating altitude: 800 to 1114hPa (6194ft to -2484ft). Operating temperature: 41 ˚ F to 95 ˚ F.
Storage Altitude: 300 to 1114hPa (31,912 to -2484ft). Storage temperature: 5 ˚ F to 140 ˚ F.
Frequent use of the Power ON or OFF might trigger the power protection circuit. If the TV
does not turn ON, please wait a little before turning ON again.
1 Arching sound from
plasma display monitor’s
panel.
2 Interference for infrared
equipment.
3 Bright and dark spots
4 Picture Image (Spectrum)
5 Display panel surface
temperature is too high
6 Plasma Surface
7 Transportation
8 Image retention
9 Luminosity and contrast
10 Granular spots
11 Disturbance to video
apparatus
12 Lip Sync
13 About the use
environment of PDP
television (temperature)
14 Caution on prolonged
storage
15 Operating
16 Storage
17 Power ON or OFF
No. Items Notes
IMPORTANT NOTES
BASIC OPERATION