— 12 —
KV-29FV16A
3-1.
X
R530, R531 CONFIRMATION
METHOD (HOLD-DOWN
CONFIRMATION) AND
READJUSTMENTS
Always perform the following adjustments when replacing the following
components marked with a
Y
mark on the schematic diagram:
Part Replaced (
Y
)
A BOARD:
C531, C532, D302, D519, D520,
D521, IC355, IC501, Q301, R356,
R359, R361, R529, R530, R531,
R532, R533, R550, T503
GA BOARD
IC6003, R6088
Adjustment (
X
)
A BOARD:
R530, R531
PREPARATION BEFORE CONFIRMATION
1. Turn the POWER switch ON.
2. Input a white signal and set the PICTURE and BRIGHT controls to
maximum.
3. Con
fi
rm that the voltage of more than 23.0 VDC appears between
TP85 and ground on the A Board.
4. Using a Variac, apply AC input voltage: 120 ± 2.0 VAC.
5. Input a white signal and verify that the I ABL is within the sepci
fi
ed
range: 1730.0 ± 100µA, +B = 135.0 ± 1.0 V DC.
At AC input: 120.0 ± 2.0 V AC.
+
I ABL
ABL
T503
FBT
-
ammeter
3.0 mA DC
range
A
6. Record the voltage between TP 85 and ground.
7. Using an external DC power supply, apply voltage between TP85 and
ground. Increase the voltage gradually and con
fi
rm that the hold
down works (raster disappears) at lower than the voltage recorded
in Step 6.
T503
FBT
TP85
R531 R530
DC Power Supply
digital
multimeter
+
-
+
-
+
-
A
ammeter
3mA DC ra
nge
Lower than 24.78 ± (-0.1) V DC.
At AC input 120.0 ± 2.0 V AC.
8. A BOARD - CONDUCTOR SIDE: Con
fi
rm that a voltage appears
between TP85 and ground of more than 21.0 V DC.
3-2. B+ VOLTAGE CONFIRMATION AND
ADJUSTMENT
Always perform the following adjustments when replacing the following
components, which are marked with
Y
on the schematic diagram on
the GA Board:
GA BOARD:
IC6003,
R6088
1. Using a Variac, apply AC input voltage: 130 ± 2.0 VAC
2. Input a monoscope signal.
3. Set the PICTURE control and the BRIGHT control to initial reset
value.
4. Con
fi
rm the voltage of GA Board CN6007 between pin
1
to ground
is less than 135.0 ± 1.5 V DC.
5. If step 4 is not satis
fi
ed, replace the R6088 on GA Board and repeat
the above steps.
SECTION 3: SAFETY RELATED ADJUSTMENTS