Safety Related Adjustments; R582 And R584 Confirmation Method (Hv Hold-Down Confirmation And Readjustments); B+ Voltage Confirmation And Adjustment - Sony TRINITRON KV-27S42 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, C508, C505, C507, C509, C511, C515, C520, C573,
C574, C575, D572, D573, D574, IC301, IC521, IC602, L591,
L501, R582, R583, R585, R578, R586, R625, R626, T504
Preparation Before Confirmation
1. Using a Variac, apply AC input voltage: 120 ± 2 VAC
(or 120-220 ± 2 VAC for KV-29AL42/29AL42C/29AL66/
29AL66C/29SL42/29SL42C/29SL46/29XL42M 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/-95 A.
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: less than or equal to 141.3 VDC).
8. Input a white signal and set PICTURE and BRIGHTNESS
to maximum.
9. Repeat steps 4 to 7.
SECTION 4

SAFETY RELATED ADJUSTMENTS

— 17 —
KV-27S42/27S46/27S66/29AL42/29AL42C/29AL66/
29AL66C/29SL42/29SL42C/29SL46/29XL42M
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, components marked
with .
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 schematic diagram.
IC601, IC602
1. Using a Variac, apply AC input voltage: 130 ± 2 VAC
(or 120-220 ± 2 for KV-29AL42/29AL42C/29AL66/
29AL66C/29SL42/29SL42C/29SL46/29XL42M only.)
2. Input a dot signal.
3. Set the PICTURE and BRIGHTNESS controls to minimum.
4. Set to service adjustment mode.
5. Select PADJ with and
6. Adjust with to the 0 level.
7. Confirm that the voltage of A Board TP-600 is less than
138 VDC.
8. If step 7 is not satisfied, replace the components listed
above, then repeat the above steps.
9. Adjust with and for: 135+ 3 VDC
10. Write into the memory by pressing
.
T504
FBT
ammeter
3.0 mA DC
range
ABL
-
+
A
IABL
.
then