JVC AV-27F476 Service Manual page 23

4.8 ADJUSTMENT PROCEDURE
4.8.1 CHECK ITEM
Measuring
Item
instrument
B1 VOLTAGE DC voltmeter S1 Connector
HIGH VOLTAGE Resistor
HOLD DOWN (22.0kΩ, 1/4W)
RESISTOR
B1
5 4 3
4.8.2 FOCUS
Measuring
Item
instrument
FOCUS Signal
generator
4.8.3 DEFLECTION CIRCUIT
Measuring
Item
instrument
V. SIZE / Signal
V. POSITION generator
(4:3)
Remote
control unit
Screen
size
Test point Adjustment part
1-pin : TP-E
5-pin : TP-91B
[MAIN PWB]
S1 connector
2-pin : X-RAY2
3-pin : X-RAY1
[MAIN PWB]
2 1 S1 CONNECTOR
Test point Adjustment part
FOCUS VR
[In HVT]
Test point Adjustment part
[2.DEF (D)]
D05: V PHASE
D07: V SIZE
D11: VS CORR
D13: V LIN
V. CENTER SW
(S1421)
[MAIN PWB]
Picture
size
100%
(1) Receive the black and white signal. (color off)
(2) Connect the DC voltmeter to the 1-pin and 5-pin of
S1 connector.
(3) Confirm that the voltage is DC134.5V±2V.
• After repairing the high voltage hold down circuit. This
circuit shall be checked to operate correctly.
(1) Turn the power switch to on.
(2) Refer to the figure, connect the resistor between S1
connector 2-pin and 3-pin.
(3) Make sure that the screen picture disappeares.
(4) Disconnect the power plug.
(5) Remove the resistor.
(6) Again connect the power plug.
(7) Turn the power switch to on.
HEATER
(8) Make sure that the normal picture is displayed on the
screen.
HVT
4
(1) Receive the crosshatch signal.
(2) While watching at the screen, adjust the FOCUS VR
to the vertical and horizontal lines will be thinnest
and sharpest center horizontal line.
(3) Make sure that the picture is in focus even when the
screen gets darkened.
(1) Receive the crosshatch signal.
(2) Select 2.DEF(D) from the SERVICE MODE.
(3) Select < D05 > (V PHASE).
(4) Set the initial setting of < D05 >.
(5) Adjust V. CENTER SW to agree the vertical center
with display center.
(6) Select < D07 > (V SIZE).
(7) Adjust < D07 > to the vertical screen size become
setting value is 92%.
NOTE:
• Bottom is to be located within the 85%-95% range.
• When vertical linearity is not even, adjust < D13 > (V
LIN) and < D11 > (VS CORR) to vertical linearity
Description
Description
Description
(No.YA243)1-23