Hitachi 32UX01S, Service Manual

Page: 45 / 92

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6. AUDIO OUT LEVEL CHECK
Adjustment Preparation
(1) Input the same audio signal at item 1(2) to AUDIO
IN terminal (L). At this time, connect nothing to R
terminal.
(2) Input the same audio signal as item 1(2) to
AUDIO:1 IN terminal (R). At this time, connect
nothing to L terminal.
(3) Check that the normal sound is output from both
sides of the speakers when signal in item (1) is
input.
(4) Check that the normal sound is output from only
the right (R) speaker when signal in item (2) is
input.
Adjustment Procedure
(1) Check that the audio output of AUDIO AMP con-
nected to AUDIO HiFi OUT terminal changes
according to the “VOLUME” of the set.
(2) Confirm that the output level of item (1) should be 1
Vrms (2.8 Vp-p)
앐
20%. (Above level is equivalent to
VOL. MAX. 100% modulated signal input.)
XII. SAFETY CHECK
1. POLARITY CHECK
This check is performed according to UL standard
requirement. There should be electricity between
AC Power Cord and Chassis Earth.
XlII. MTS OPERATION CHECK
1. STEREO/SA BROADCAST RECEIVING CHECK
Adjustment Preparation
(1) Set the TV set so that a MTS broadcast
(STEREO/SAP) can be received.
(2) Set MTS mode to STEREO or SAP mode.
Note: To select between “STEREO/SAP,”
display sound setting of MTS mode and
Select AUDIO MENU
(3) Set BALANCE to the center.
Adjustment Procedure
(1) When one of the MTS broadcast stereo SAP is
received, check that “ST” or “SA” is displayed on
the screen.
(2) Stereo broadcast receiving check
(a) Select MTS mode and press cursor
왘
button
to display “STEREO” on the screen.
(b) When only Lch signal is received, Lch sound
comes out from the left speaker.
(c) When only Rch signal is received, Rch
sound comes out from the right speaker.
(d) When monaural signal is received, monaural
sound comes out from both the right and left
speakers.
(3) SAP broadcast receiving check
(a) Select MTS mode. Press cursor
왘
button to
display “SAP” on screen.
(b) SAP signal comes out from both of the right
and left speakers.
(c) When to SAP signal, the sound on “MAIN”
side (refer to (3)) comes out.
Note: When the RECALL button is operated,
“STEREO”, “ST” or “SA” are shown for
approx. for 4 sec.
2. MTS MODE CHECK
Adjustment Preparation
(1 ) Set the TV set so that a MTS broadcast
(STEREO/SAP) can be received.
(2) Set BALANCE to the center.
Adjustment Procedure
(1) When “MTS MODE” is set to “MONO” mode,
check that STEREO indication which has been ON
are turned OFF and that monaural sound comes
out from the right and left speakers.
(2) When “MTS MODE” is set to “STERO” mode,
check that the STEREO indication which has been
OFF are turned ON and that STEREO and SA
sound can be received.
3. STEREO SEPARATION CHECK
Adjustment Preparation
(1 ) Set the set so that a MTS broadcast
(STEREO/SA) can be received.
(2) Make surround “OFF”.
(3) Set MTS MODE to “STEREO.”
(4) Connect AUDIO OUT terminals L and R to an
oscilloscope.
Adjustment Procedure
(1) When stereo L only signal (or R only signal) is
received, check that the output level ratio of Lch
and Rch is 15dB or more.
(Example)
When L only is received (100% modulation)
STEREO
ST/SA
ANT A 13
CH Output Level
L 1.2 Vpp
R 0.21 Vpp or less