Comb Filter Operation Check; Audio Operation Check; Tone Control Operation Check; Perfect Volume Operation Check - Hitachi DP05 Service Manual

1.2 Comb filter operation check

Adjustment preparation
(1) Receive the color bar signal at the regular tun-
ing point.
(2) Set the CONTRAST control to MAX and the
other controls to center.
(3) Set the A.I. to OFF.
Adjustment procedure
(1) Check that between the color bars there are not
line dots every second color bar as shown in the
drawing.
A
Check A and
A
B

1.3 AUDIO OPERATION CHECK

1.3.1 TONE CONTROL CHECK
Preparation for adjustment
(1) Input an audio signal of 250Hz and 3Khz in
order with level of 150mVrms to the L/mono
audio input.
(2) Set the Volume to around the center.
(3) Set SRS SURROUND to OFF.
(4) Set LOUDNESS to OFF.
(5) Set INTERNAL SPEAKER to ON.
Adjustment Procedure
(1) Select BASS mode and check that the audio
output level of the speakers changes to
emphasized or supporessed when adjust to
max. or min. of the adjustment mode.
(2) Select TREBLE mode and check that the
audio output level of the speakers changes
by emphasized or suppressed when adjust to
max. or min. of the adjustment mode.
(3) Select BALANCE mode and check that the
audio output changes right or left when adjust
to right or left of the adjustment mode.

1.3.2 PERFECT VOLUME OPERATION CHECK

Preparation for adjustment
(1) Set PERFECT VOLUME to ON.
(2) Set the Volume to around the center.
(3) Set INTERNAL SPEAKER to on.
Procedure
(1) Input 100mVrms, 200mVrms, 300mVrms and
400mVrms of 1KHz sound signal to L/MONO
terminal.
(2) Check same level sound is output from SP
when 200mVrms, 300mVrms and 400mVrms
of 1KHz sound signal is input.
A A
B
line dots.
B
43/53FDX01B
No Dots
No Dots
1.3.3 SRS CHECK
Preparation for adjustment
(1) Set the Master Volume to around the center.
(2) Set the BALANCE to the center.
(3) Set the BASS and TREBLE to the center.
(4) Set the LOUDNESS to OFF.
(5) Set PERFECT VOLUME to OFF.
(6) Set INTERNAL SPEAKER to ON.
(7) Input the audio signal of 400Hz in order with
level of 1Vpp to the R audio inpu and no signal
to the L audio input.
Adjustment Procedure
(1) Check the following wave form at the HiFi out.
OUTPUT
HiFi L out 1.4±0.05Vpp
HiFi R out 1.9±0.05Vpp
15
SRS
ON OFF
No signal
0.7±0.05Vpp