Table of Contents
Advertisement
A
BOARD
R582 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:
IC301, IC521, IC602, D572, D573, D574, DY,
C511, C574, C575, R578, R582, R583, R584,
R585, R586,R625, R626, R634, R635, T504 (FBT)
(1) Preparation before Confirmation
1) Turn the POWER switch ON. Input an entirely white
signal and set the PICTURE and BRIGHT controls to
maximum.
2) Confirm that the voltage between C574(+) and ground is
more than:
99.8VDC
when the set is operating normally with 120.0-240.0 ± 2.0
VAC.
(2) 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.
2) Input a dot signal and set PICTURE and BRIGHTNESS to
minimum:
IABL = 95+100/-95µA
3) Confirm the voltage of A board TP-600 is
116.8 ± 0.3VDC
4) Connect the Digital Voltmeter and the DC power supply
via diode 1SS119 to C574 (+). (See figure 1.0 on next page.)
5) Increase the DC power voltage gradually until the picture blanks out.
6) Read the digital voltmeter indication.
7) Turn DC power source off immediately.
STANDARD
Less than or equal to:
8) Input a white signal and set PICTURE and BRIGHTNESS to Max
9) Repeat steps from (4) to (7).
STANDARD
Less than or equal to:
127.3 VDC
SECTION 4
SAFETY RELATED ADJUSTMENTS
(3) Hold-down Readjustment
127.3 VDC
— 21 —
If the current setting indicated in step 2-2 cannot be met,
readjustment should be performed by altering the resistance
value of R582, a component marked with
ABL
B+ VOLTAGE CONFIRMATION AND ADJUSTMENT
The following adjustments should always be performed
when replacing the following components which are marked
with ] on the schematic diagram:.
IC001, IC602, R030, R626, R632,
R633, R635, R636, R637, R638, R639
1) Supply 130 ±
2.0
VAC to the set with a variable auto
0
transformer.
2) Input a dot signal.
3) Set the PICTURE control and the BRIGHT control to
minimum condition.
4) Set to service adjustment mode.
5) Select PADJ with
and
6) Adjust with
to the 0 level.
7) Confirm the voltage of A BOARD TP-600 is less than
125V DC.
8) If step 7 is not satisfied, replace the components, repeat the
above steps.
9) Supply 120.0 ± 2.0 VAC to the set with a variable auto
transformer.
10) Adjust with
and
for:
11) Write into the memory by pressing
KV-21XE40B
.
T504
FBT
ammeter
3.0 mA DC
range
-
+
A
I ABL
.
116.8 ± 0.3V DC
then
.
Advertisement
Table of Contents
