Sony Trinitron KV-25XBR Service Manual page 24

regulated-de
power supply
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digital
multimeter
[E]
Ll~
digital
multimeter
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lo
Ll
digital
multimeter
l~~I I
'I
1',,
regulated-de
power supply
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I
Confirming of Hold Down Circuit
I
B
R1531, R1534, R1535, R1556, R1578
Perform the adjustment below when replacing any of the
following components.
Regarding components of BR1531 (HV HOLD DOWN)
[,jjl D1502, D1507, IC1501, Q1502, Q1503, R427, R431
R437, R438, R1512, R1519, R1529, R1530, R1531,
R1532, R1533, R1543, R1544, R1545
Confirmation method
(1) +B MAX confirmation
1) Set AC be 130
~g
V and distortion rate be less
than 3%, and receive monosco and reset picture
and brightness.
2) At this point, the voltage on the 140V line
should be less than 141.5V DC.
(2) Operational confirmation of detected voltage
1} Set AC be 120V
±
3V and distortion rate be less
than 3%, and receive entire white signal, and
set the picture and brightness at MAX.
2) At this point comfirm that the voltage more than
11.0V DC is appeared on TP85.
3) lnaddition, confirm that TPB5 holds down when
15.19
~8:8
5
V DC isapplied to it.
4) Confirm that TP85 does not hold down when the
voltage of 14.58
~8:8
5
V DC is applied to it.
5) Set AC be 120V±3V and distortion rate be less
than 3%, and receive dot signal and set the
picture and brightness at MIN.
6) Confirm that TP85 holds down when 16.29
+o.o V DC . ,. d .
_ 0 _ 05 Is app Ie to It.
7) Confirm that TP85 does not hold down when
15. 77
~8:8
5
V DC is applied to it.
IV.
SIZE CONFIRMATION
I
* The following adjustments should always be performed
when replacing the following components (marked with
l:i
on the components circuit}.
*
Regarding components of
B
R1578 (V. SIZE)
'i:iiiC1519,
C1663, C1664, C1667, C1675, IC1501,
L1514, R1522, R1578, R1579, R1580, R1581,
R1582, R1583, RV1503, FBT, DY
1. Receive monoscope signal.
2. PICTURE }
BRIGHTNESS RESET
3. Confirm that the V. SIZE at minimum should not exceed
14.6 frames by adjusting RV1503 (V. SIZE).
I
H. SIZE CONFIRMATION
I
*
The following adjustments should always be performed
when replacing the following components (marked with
'i:iii
on the components circuit).
*
Regarding components of
B
R1556 (H. SIZE)
'i:iii
C1663, C1664, C1667, C1675, IC1502, L 1514,
R1556, R1570, R1635, R1636, R1638, RV1511,
FBT, DY
1. Receive monoscope signal.
2. PICTURE }
BRIGHTNESS RESET
3. Confirm that the H. SIZE should be within 11.3 to 14.0
fra-nes when adjusting the H. SIZE (RV1511) to maxi-
mum.
- 29-
KV-25XBR
RM-724/APM-X3U
I
PROTECROE CONFIRMATION
I
*
The following adjustments should always be performed
when replacing the following components (marked with
'i:iii
on the component circuit).
* Regarding components of
B
R1534, R1535 (PRO-
TECTOR)
'i:iii
D 1508, D1509, IC301, IC401, 01506, R339, R340,
R348, R436, R1534, R1535, R1537, R1538, R1539,
R 1561, R 1576
1. Receive color bar signal.
2. Turn the power supply of the set to ON.
3. PICTURE
l
BRIGHTNESS~ maximum
COLOR
J
4.
Apply DC 125.3~~
2
V externally to +Bline, and confirm
that the PROTECTOR CIRCUIT becomes active and the
raster disappears from the screen.
SAFETY RELATED ADJUSTMENT
am~:1
t
i
3.0mA de I :
I I
range
L __
..J
NL901
+ -
---------.--....--<>--~
~
IC1501
ABL
I ABL
I
C901
icoNFIRMING oF HV HOLD DOWN (BR1531JI
When repiacing the foiiowing components (marked with
Ci
on the schematic diagram), perform the adjustment as
follows.
[,ii
D1502, D1501, IC1501, Q1502,O1503,R421, R431
R437, R438,R1512, R1519, R1529, R1530,R1531,
R1532,R1533,R1543, R1544, R1545
( 1) Before Adjustment
1 . .Supply 120V ac and the POWER switch set to ON.
2. Confirm that there is more than 11.0 V at the hold
down check point TP-85.
3. The POWER switch turns OFF.
(2) Readjustment Procedure
1. Disengage ABL terminal of FBT from the foil and con-
nect the ammeter as shown to measure the ABL terminal
current.
KV-25XBR
RM-724/APM-X3U
2. Supply 120V ac and the POWER switch sets to ON.
3. Apply 135V to TP91 from and external DC power
supply.
4. Receive a stable signal such as an a/I-white signal and
adjust ABL current to 1600± TOµA with PICTURE,
BRIGHT,
etc.
VRs.
5. Confirm that the HV HOLD DOWN CIRCUIT operates
and that raster disappears when 15.19~~-g~v is applied
· to hold down check point TP-85 from an external DC po-
wer supply.
Note: When raster disappears, cut input voltage and
applied voltage immediately.
6. Confirm that the HV HOLD DOWN CIRCUIT does not
Ir, r11::
operate when 14.58=a:oo V is applied to hold down
check point TP-85 from an external DC power supply.
Note:
If the HV HOLD DOWN CIRCUIT operates, im·
mediately cut input and applied voltage.
7. Receive a stable signal such as a dot signal and adjust ABL
current for 200± TOµA with PICTURE and BRIGHT VRs.
8. Confirm that the HV HOLD DOWN CiRCUiT does not
operate when 15. 77+ 0 o.O~ V is applied to hold down
- .00
check point TP-85 from an external DC power supply.
Note: If the HV HOLD DOWN CIRCUIT operates, im-
mediately cut input and applied voltage.
9. Confrim that the HV HOLD DOWN CIRCUIT operates
and raster disappears when 16.29~g:g~ V is applied to
hold down check point TP-85 from an external DC pow-
er supply.
Note: When raster disappears, cut input voltage and
applied voltage immediately.
TO.Adjust R1531 so that steps 5, 6, 8 and 9 are satisfied.
11. The POWER switch turns OFF.
12. Remove external DC power supply and DC ammeter.
13. Solder FBT ABL pin.
I
CHECKING AFTER H. V.R. REPLACEMENT
I
After replacing H. V.R., *comfirm that there is more than
11.0 Von HOLD DOWN check point TP-85.
• This check is to be performed when H. V.R. only is re-
placed, and has no relation to the HV hold down circuit
readjustment for replacement of parts marked [,jjl .
!MAXIMUM +B VOLTAGE CONFIRMATION
I
1. Supply 130 V ac to with variable auto-transformer.
2. Tune in an off air signal.
3. Set the PICTURE control to initial setting and BRIGHT
control to mechanical center.
4. Confirm the voltage on digital multimeter is less than
141.5Vdc.
5.
If
step 4 is not satisfied, replace IC651 on GB borad and
repeat above steps.
!CHECK AFTER IC651 REPLACEMENT
i
1. Supply 130 Vac to with variable auto-transformer.
2. Tune in an off-air signal.
3. Set the PICTURE control to initial setting and BRIGHT
to mechanical center.
4. Confirm tha voltage of TP91 is less than 141. 5 V de.
5. If step 4 is not satisfied, replace IC651 in GB.board and
repeat above spteps. ·
I
CONFIRMATION OF H.SIZE (BR1556JI
Perform the adjustment below when replacing any of the
following components.
~
C1663, C1664, C1667. C1675, IC1502, L1514,
R1556, R1570, R1635, R1636, R1638, RV1511,
FBT, DY
Confirmation method
1. Receive monoscope signal.
PICTURE . ........... } RESET
BRIGHTNESS . ...... .
3. Confirm that the H.SIZE should be within 11.3 to
14.0 frames when adjusting the H.SIZE (RV1511) to
h1aJ<.irr,urn.
jcoNFIRMATION OF v.s1zE rBRT57BJj
Perform the adjustment below when replacing any of the
following components.
~ C1519, C1663, C1664, C1667, C1675, !C1501,
L1514, R1522, R1578, R1579, R1580, R1581,
R1582, R1583, RV1503, FBT, DY
Confirmation method
1.
2.
3.
Receive monoscope signal.
PICTURE . .. : ........ } RESET
BRIGHTNESS . ...... .
Confirm that the \I.SIZE at minimum should not
exceed 14.6 frames by adjusting RV1503"(V.SIZE).
jcoNFIRMATION OF PROTECTOR (BR1534, R1535J
I
Perform the adjustment below when replacing any of the
following components.
~ D1508,
D1509, IC301, IC401, Q1506, R339, R340,
R348, R436, R1534, R1535, R1537, R1538, R1539,
R1561, R1576
Confirmation method
1.
2.
3.
4.
Receive color bar signal.
Turn the power supply of the set to ON
PICTURE ........... . 1
BRIGHTNESS . .......
~
maximum
COLOR ............ .
J
Aplly DC 125.3
~g-
2 V externally
to +Bline, and
confirm that the PROTECTOR CIRCUIT becomes
active and the raster disappears from the screen.
~
30-