Safety Related Adjustments; R584 Confirmation Method (Hv Hold-Down Confirmation And Readjustments); B+ Voltage Confirmation And Adjustment - Sony TRINITRON KV-27V42 Service Manual

4-1. R584 CONFIRMATION METHOD
(HV HOLD-DOWN CONFIRMATION)
AND READJUSTMENTS
The following adjustments should always be performed when
replacing the following components which are marked with
on the schematic diagram.
DY, C511, C573, C574, C575, D572, D573, D574,
R582, R583, R585, R586, R578, R625, R626, T504, IC301,
IC521, IC602, C507, C508, C505, C509, C515, C520, L591,
L501
Preparation Before Confirmation
1. Using a Variac, apply AC input voltage: 120 ± 2 VAC
(or 120-220 ± 2 VAC for KV-29SL42K).
2. Turn the POWER switch ON.
3. Input an entirely 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
(T504) and the PCB land where Pin 11 would normally
attach. (See Figure 1 on the following page.)
2. Input a dot signal and set PICTURE and BRIGHTNESS
to minimum: IABL = 100 + 100/-95
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 following page.)
5. Increase the DC power voltage gradually until the picture
blanks out.
6. Read the digital voltmeter indication.
(standard: less than or equal to 141.3 VDC).
7. Turn DC power source off immediately
8. Input a white signal and set PICTURE and BRIGHTNESS
to maximum.
9. Repeat steps 4 to 7.
SECTION 4

SAFETY RELATED ADJUSTMENTS

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 R584, a component marked
with
4-2. B+ VOLTAGE CONFIRMATION AND
Note: The following adjustments should always be performed
when replacing the following components, which are marked
with
A .
1. Using a Variac, apply AC input voltage: 130 ± 2 VAC
m
2. Input a dot signal.
3. Set the PICTURE and BRIGHTNESS controls to minimum.
4. Set to Service Adjustment Mode.
5. Select PADJ with
6. Adjust with
7. Confirm the voltage of A board TP-600 is less than
8. If step 7 is not satisifed, replace the components and repeat
9. Supply 120 ± 2 VAC (or 120-220 ± 2 VAC for KV-
10. Adjust with
11. Press
— 17 —
KV-27V42/27V66/29SL42K/29SL42T/29VL42T/29XL42T
.
ABL
ADJUSTMENT
on the schematic diagram.
IC601, IC602
(or 120-220 ± 2 VAC for KV-29SL42K).
and
to the 0 level.
138 VDC.
the above steps.
29SL42K) to the set with a variable auto transformer.
and for 135 ± 3 VDC.
then
T504
FBT
Ammeter
3.0 mA DC
Range
-
+
A
I ABL
.
to save into the memory.