Safety Related Adjustments; R582 And R584 Confirmation Method (Hv Hold-Down Confirmation And Readjustments); B+ Voltage Confirmation And Adjustment - Sony TRINITRON KV-20FV10 Service Manual

KV-20FV10/21FV10/21FV10C/25FV10A
4-1. R582 AND R584 (R584 for KV-25FV10A
ONLY)CONFIRMATION METHOD
(HV HOLD-DOWN CONFIRMATION) AND
READJUSTMENTS
The following adjustments should always be performed when
replacing the following components which are marked with
the schematic diagram:
Part Replaced ( )
DY, CRT, C507, C520, C573, C574,
C575, D572, D573, D574, IC521,
IC301, R578, R579, R582, R583,
R585, R586, R587, T504,
T505..................................A B
Preparation Before Confirmation
1. Using a Variac, apply AC input voltage: 120 ± 2 VAC
(or 120-220 ± 2 VAC for KV-21FV10/21FV10C/25FV10A
only).
2. Turn the POWER switch ON.
3. Input a white signal and set the PICTURE and
BRIGHTNESS controls to maximum.
4. Confirm that the voltage between C574 (+) or TP503
and ground is more than 105 VDC.
Hold-down Operation Confirmation
1. Connect the current meter between Pin 11 of the FBT
(T505) and the PWB land where Pin 11 would normally
attach. (See Figure 1 on the next page.)
2. Input a dot signal and set PICTURE and BRIGHTNESS
to minimum: IABL = 100 ± 100
3. Confirm the voltage of A Board TP-600 is 135 ± 3 VDC.
4. Connect the digital voltmeter and the DC power supply
via diode 1SS119 to C574 (+) and ground. (See Figure 1
on the next page.)
5. Increase the DC power voltage gradually until the picture
blanks out.
6. Turn DC power source off immediately.
7. Read the digital voltmeter indication
(standard: 115.7 ± .3 VDC)
(standard: 138.0 ± .3 VDC KV-25FV10A ONLY).
8. Input a white signal and set PICTURE and BRIGHTNESS to
maximum: IABL = 1350 ± 100
IABL = 1650 ± 100
9. Repeat steps 4 to 7.
SECTION 4

SAFETY RELATED ADJUSTMENTS

Adjustment ( )
HV HOLD-DOWN
(R582, R584)
oard
A .
m
A
m
A (KV-25FV10A ONLY)
m
Hold-down Readjustment
If the setting indicated in step 2 of Hold-down Operation
Confirmation cannot be met, readjustment should be performed
by altering the resistance value of R582 and/or R584 components
marked with .
on
4-2. B+ VOLTAGE CONFIRMATION AND
ADJUSTMENT
Note: The following adjustments should always be performed
when replacing the following components, which are marked with
on the schematic diagram on the G Board.
G BOARD: IC601, PH600
1. Using a Variac, apply AC input voltage: 130 ± 2 VAC (or 120-
220 ± 2 VAC for KV-21FV10/21FV10C/25FV10A only).
2. Input a dot signal.
3. Set the PICTURE and BRIGHTNESS controls to minimum.
4. Confirm that the voltage of A Board TP-600 is 135 ± 3 VAC.
5. If step 3 is not satisfied, replace the components listed above,
then repeat steps 1–3.
— 20 —
T505
FBT
ammeter
3 0 mA DC
range
ABL
-
+
A
IABL