Safety Related Adjustments; R530, R531 Confi Rmation Method (Hold-Down Confi Rmation) And Readjustments; B+ Voltage Confi Rmation And Adjustment - Sony Trinitron KV-29FV300 Service Manual

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 (
)
A BOARD:
R550, T503, T504, D519,
IC501, R533, D521, R532,
D520, C531, R529, R530,
R531, C532
PREPARATION BEFORE CONFIRMATION
1. Using a Variac, apply AC input voltage: 120+2.0 VAC.
2. Turn the POWER switch ON.
3. Input a white signal and set the PICTURE and BRIGHT controls to
maximum.
4. Confi rm that the voltage of more than 23.0 VDC appears between
TP85 and ground on the A Board.
HOLD-DOWN OPERATION CONFIRMATION
1. Connect the current meter between Pin 11 of the FBT (T503) and the
PWB land where Pin 11 would normally attach. (See Figure 1).
2. Input a dot signal and set PICTURE and BRIGHTNESS to minimum:
IABL = 2175 + 100/ -325 µA.
3. Confi rm the voltage of A Board TP91 is 135 ± 1.5 VDC.
4. Connect the digital voltmeter and the DC power supply to TP85 and
ground. (See Figure 1 above).
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 = 27.24 + 0.0/ - 0.1
VDC).
8. Input a white signal and set PICTURE and BRIGHTNESS to
maximum: IABL = 2175 + 100/ -325 µA.
9. Repeat steps 4 to 7.
SECTION 3: SAFETY RELATED ADJUSTMENTS
Adjustment (  )
HV HOLD DOWN
R530, R531
HOLD-DOWN READJUSTMENT
If the setting indicated in Step 2 of Hold-Down Operation Confi rmation
cannot be met, readjustment should be performed by altering the
resistance value of R530, R531 component marked with X.
R531 R530
DC Power Supply
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 GK Board:
GK BOARD: IC600, PH602
1. Using a Variac, apply AC input voltage: 130 + 2.0/-0.0 VAC
2. Input a monoscope signal.
3. Set the PICTURE control and the BRIGHT control to
minimum.
4. Confi rm the voltage on A Board between TP23 and ground is less
than 136.5 VDC.
5. If step 4 is not satisfi ed, replace R530 and R531 on A Board and
repeat the above steps.
— 16 —
KV-27FV300/29FV300/32FV300/36FV300
digital multimeter
+
-
T503
TP85
TP85
FBT FBT
ammeter
3mA DC range
+
-
A
+
-
Figure 1