Sony KDL-55W900A - Manual (Page 213)

Perform [Fine Tune]/[AFT] to obtain better picture reception. (Option name
differs depending on your region/country.)
Set [Audio Filter] to [Off], [Low] or [High] to improve sound for analog
reception. ([Audio Filter] may not be available depending on your
region/country.)
Set [LNA] to [Off] to improve picture reception. ([LNA] may not be available
depending on the situation/region/country.)
You cannot receive any channels.
Check the antenna/cable connection.
Make sure the [Cable/Antenna] setting is correct for your TV signal source.
If using CATV STB, refer to its instruction manual for installation.
You cannot receive or select channels.
Perform [Auto Program] to add receivable channels that are not present in
the TV’s memory.
To receive or select cable channels, make sure that signal type in the
channel settings is set to [Cable].
To receive or select channels by antenna, make sure signal type is set to
[Antenna].
Some digital cable channels are not displayed.
Certain cable companies have limitations on the broadcast of digital cable
channels. Check with your cable company for more information.
The digital cable channel may be set to [Hidden] in [Show/Hide Channels].
Broadcast HD formats have poor quality.
Content and signal quality are regulated by the signal provider. Many HD
channels and content are actually upscaled versions of standard-definition
broadcasts. The picture is affected by the quality of the signal received,
which varies between channel and program.
Noisy picture.
Make sure that the antenna is connected using a 75-ohm coaxial cable.
Keep the antenna cable away from other connecting cables.
To avoid TV interference, make sure to use an undamaged antenna cable.
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