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3.7 ADJUSTMENTS PROCEDURE
3.7.1 B1 POWER SUPPLY VOLTAGE CHECK
Measuring
Item
instrument
B1 POWER
DC voltmeter TP-91 (B1)
SUPPLY
check
3.7.2 TUNER CIRCUIT / FOCUS
Measuring
Item
instrument
IF VCO
Remote
control unit
TOO HIGH
ABOVE REFERENCE
BELOW REFERENCE
TOO LOW
SYNC
:
YES
RF AGC
Remote
control unit
Setting item
19. RF AGC
FOCUS
Signal
generator
Remote
control unit
Test point
Adjustment part
TP-E
Test point
Adjustment part
[VCO(CW)]
CW transf. (T131)
YELLOW
EXIT BY
EXIT
[PICTURE]
<19. RF AGC>
Initial setting value
40
FOCUS VR
[In HVT]
Description
(1) Receive the black-and-white signal.
(2) Connect the DC voltmeter to TP-91 (B1) and TP-E.
(3) Confirm that the voltage is DC134V.
Description
Under normal conditions, no adjustment is required.
(1) Receive the NTSC broadcast (use channels without
offset frequency).
(2) Select the VCO(CW) mode from the SERVICE
MENU.
(3) Change [AFC] to OFF and [FINE] to 0.
(4) Confirm the color change (yellow) from [TOO HIGH]
to [TOO LOW] by CW transf., and [SYNC] is [YES]
being shown on the screen. Then, adjust CW transf.
until [BELOW REFERENCE] letters turns yellow and
confirm again [SYNC] is [YES].
(5) It returns the [AFC] to ON.
(1) Receive the broadcast.
(2) Select <19. RF AGC> of the PICTURE mode.
(3) Press the [MUTING] key and turn the color off.
(4) Get the noise in the screen with the [VOLUME (-)]
key (0 side of setting value).
(5) Press the [VOLUME (+)] key, and stop when noise
disappears in the screen.
(6) Change to other channels and make sure that there
is no irregularity.
(7) Press the [MUTING] key and get the color.
(1) Receive the crosshatch signal.
(2) While looking at the screen, adjust FOCUS VR so
that the vertical and horizontal lines will be clear and
in fine detail.
(3) Make sure that the picture is in focus even when the
screen gets darkened.
AV-20420
AV-20421
(No.52111)1-19
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