Sharp TU-DTV1000/A, Service Manual

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TU-DTV1000/A
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Service mode
DTV stands for digital television broadcast. In analog broadcast, the worse the reception condition gets, the more
noises and ghosts occur on the screen. In digital broadcast, on the other hand, there is no degraded images up to
a certain level. Once the reception condition drops below a limit, however, both picture and sound are interrupted
suddenly. With DTV sets, it is thus very difficult to know how well the radio wave is received by viewing the screen.
To cope with this problem, the service mode provides for useful information on signal reception condition on the
screen.
1) Service mode screen and switching
There are two screens for the service mode. Press the SELECT key on the set or the R/C unit, and at each push
the two screens get switched alternately.
2) Limitations with the service mode
In the service mode, channels can be selected just directly or with the CH UP/DOWN keys. Any other ways
channel selection are impossible. The usual on-screen display does not appear either.
3) Information displayed in the service mode
SERVICE MODE 1 screen
SERVICE MODE 1 V1.01
STATUS1 : TUNER/VSB
CH : **.**
VSB : LOCK/UNLOCK
NTSCIRF : ON/OFF/···
VSB MODE : 8VSB/···
SI GET : OK/NG
PACKET ERROR :
SERVICE MODE 1 :
Tells that the set is in the service mode 1.
V1.01 :
Indicates the version of the software installed in the set. Make sure the program version is up to date.
CH:**.** :
Indicates the channel that is being selected.
VSB Lock :
Shows if the VSB system is locked or unlocked.
OK : Indicates that a selected major channel has DTV programs.
NG : Indicates that a selected major channel does not have any DTV programs.
* When the VSB is unlocked, “...” is shown for the following two items.
NTRCIRF :
Shows whether the NTSC rejection filter is activated or not.
VSB Mode :
Indicates that 8VSB signals are being received.
SI GET :
Indicates that SI information is being received.
No video and audio output is possible even in the locked state, if the set is not ready to receive the SI
information.