JVC TM-A210G/C Service Manual page 22

4.7.3 HIGH VOLTAGE HOLD DOWN CIRCUIT CHECK
Measuring
Item
instrument
HIGH VOLTAGE HV voltmeter
HOLD DOWN
CIRCUIT Resistor
(33.0kΩ,
1/4W)
RESISTER
33.0k
6 4
5
4.7.4 FOCUS
Measuring
Item
instrument
FOCUS Signal
generator
1-22 (No.52119)
Test point Adjustment part
X-RAY
(S1 connector
3-pin, 4-pin)
[MAIN PWB]
1/4W
3 2 1
S1
CONNECTOR
Test point Adjustment part
FOCUS VR
[In FBT]
FOCUS POINT
Description
• 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 3-pin and 4-pin.
(3) Make sure that the screen picture disappears.
(4) Disconnect the power plug.
(5) Remove the resistor.
(6) Again connect the power plug.
(7) Turn the power switch to on.
(8) Make sure that the normal picture is displayed on the
screen.
Description
(1) Input the crosshatch pattern signal.
(2) Adjust the FOCUS VR for optimum focus where
moire is not apparent.
(3) Darken the picture and adjust the focus by turning
counter-clockwise from the position where focus is
poor.
(4) Alternately repeat the above steps to obtain the
optimum position.