Signal Circuit Operation Check; Auto Color Operation Check; Noise Reducer; Notch Filter Circuit Check - Hitachi 35UX85B/CZ68 Service Manual

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(2) Select the Video Setting option using b key.
l-3-6-2 PinP Shift mode check
Adjustment Preparation
(I) Press PinP key of R/C unit.
Adjustment Procedure
(1) Check that with each press of SHIFT key, the sub-picture
moves counterclockwise.
(3) Select Advance Settings option using b key.
(4) Select Noise Reducer mode using AT key.
Adjustment Procedure
(1) Set NOISE REDUCER:ON by pressing the b key of the
remote control transmitter, checking noise is reduced.
When sub-picture is in the upper part of the screen, the
channel number of the main picture
is in the lower right.
1.4.3 Notch filter circuit operation check
Adjustment Preparation
(1) Receive the color-bar signal.
l-3-6-3
PinP Swap mode check
Adjustment Preparation
(1) Press PinP key of R/C unit.
(2) Select the Notch Filter mode.
Adjustment Procedure
(1) Set the Notch Filter:ON by pressing the b key and check
that the dot interference on horizontal color borderline of
the color-bar is reduced.
Adjustment Procedure
(1) Check that with each press of "SWAP" key, the contents of
the main picture and sub-picture are exchanged.
(2) Set the Notch Filter:OFF by pressing the b key.
1.3.6.4 PinP Freeze (at PinP: ON)
Adjustment Preparation
(1) Connect the signal to ANT.
(2) Press PinP key of R/C unit.
Weak electric field check
Adjustment Preparation
(1) Connect one side of the 300 ohm feeder to 75 ohm-
300 ohm antenna adaptor. Beside, connect the antenna
adaptor to the VHF antenna terminal board as shown
below.
Adjustment Procedure
(1)
(2)
Check that each time "FREEZE" key is pressed, the sub-
picture alternates between moving picture and freezing
picture.
(2) Turn to No Signal condition
Adjustment Procedure
(I) Check that phenomena such as oscjllation and abnormal
beat, etc. do not occur on any channel.
/Antenna Terminal board
VHF/UHF
75 ohm - 300 ohm adaptor
Moving picture - Freezing picture
Press PinP key to remove PinP from screen.
1.3.6.5 PinP Freeze mode (at PinP: OFF)
Adjustment Preparation
(1) Connect the signal to ANT.
(2) PinP mode OFF.
2. POWER SUPPLY P.W.B.
Adjustment Procedure
(1) Press FREEZE key on the R/C unit.
(2) Check that freezing sub-picture appears.
2.1 +B Voltage Adjustment
Adjustment Preparation
(1) Set the AC input power supply tol20flV (distortion 3%
or less).
(2) Receive a color bar signal.
(3) Set the Contrast Brightness control to maximum.
(4) Measure about 30 seconds after the power is turned
on.
1.4 Signal Circuit Operation Check
1.4.1
Auto Color Operation Check
Adjustment Preparation
(1) Receive the color-bar signal.
(2) Select the Video Setting option using the k key.
(3) Select Advance Settings option using b key.
(4) Select Auto Color mode by pressing AV key.
Adjustment Procedure
(1) Connect the DC voltmeter to R908.
(2) Adjust R928 so that the indication of the DC voltmeter
is 140.0f0.3V.
Adjustment Procedure
(1) Set COLOR CONTROL:MAX.
(2) Set AUTO COLOR:OFF by pressing the b key, checking
that the red part of color-bar signal grows deeper.
(3) Return the AUTO COLOR:ON by pressing the b key.
(4) Return the COLOR CONTROL;TYPICAL.
2.2 Protection Circuit Operation Check
2. 2.1 +2OV Audio Power Supply
Adjustment Preparation
(1) CONTRAST to maximum, BRIGHTNESS to center.
1.4.2 Noise Reducer Operation Checking
Adjustment Preparation
(1) Receive the color-bar signal.
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