Safety Related Adjustment - Sony Multiscan CPD-1404S Service Manual

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SECTION 4
SAFETY RELATED ADJUSTMENT
8RV402, HV REGULATER. HV HOLD-DOWN AND BEAM
LIMIT CIRCUIT CONFIRMATION
When replacing the following components (marked with
~ on the schematic diagram), make this confirmation.
o
BOARO················IC901. IC902. IC401, 0930, C408,
DA (OC·l)
C409, C410, C412, C414, C415. C422.
C424, R41 4, R434, R435, L406,
T402 (FBT). T901, RV402,
DY (Deflection Yoke)
BOARO ............ · .. IC101, IC301, 0303, R327, R388
1.
HV REGULATER CIRCUIT CONFIRMATION
1) Receive a signal of fH
=
48kHz
2) Set the CONT and BRIGHT controls to minimum.
(Cut·Off condition).
3) Connect a digital multimeter to pin (g) of P402
on 0 board.
4)
Confirm the voltage is less than 6.48V ~C.
5) If step 4) is not satisfied, adjust them with
RV402.
2. HV.
HOL~-~OWN
CIRCUIT CONFIRMATION
1) Receive a signal of fH
=
48kHz.
2) Set the CONT and BRIGHT controls to minimum.
(Cut·Off Condition).
3) Apply an external DC voltage gradually to pin
(g) of P402 on 0 board, confirm that the minimum
voltage is less than 7.40 V DC where by the
HOLO·OOWN circuit operates immediately and
raster disappears.
3. BEAM LIMITER CIRCUIT CONFIRMATION
1) Receive a signal of fH
=
48kHz.
2) Adjust CONT and BRIGHT controls so that the
screen luminance to become 100 NIT.
CONT control .......... maximum
BRIGHT control· ...... centre
3) Connect a digital multimeter to pin
CD
of P402
on 0 board.
4) Confirm that the voltage is - 2.80
±
1 .00 V DC
5) Apply an external DC voltage gradually to pin
CD
of P402 on 0 board, and when the voltage
becomes more than - 11.30V, confirm the BEAM·
LIMITER circuit operates and raster disappers.
NOTE: After adjustment, cover on
8
RV402
with seal cap as follows.
CD
Insert in seal cap with RTV (silicone) as follows.
CAP
seal cap (3-710-578-01)
RTV (KE-490, 7-322-065-19)
(g) Cover the seal cap on RV402, and make paste together
silicone and printed board.
8
WARNING:
IF RV 402 (sealed variable resistor) replacement
is required, federal require that after adjustment the
control is to be sealed so no further adjustment
can be made to this resistor.
loVp CIRCUIT CONFIRMATION
I
When replacing following components, perform this
confirmation.
D BOARD .... · .. · 0901, R922, R923, 0927. 0928. 0929
1. Turn OFF the POWER switch.
2. Remove P903 and P904 connectors from 0 board.
3. Apply an external DC voltage of less than 216.00
V DC (SET UP THE CURRENT LIMITER TO 0.2
A) to pin
®
of P903 on 0 board for two second.
4. At the moment (item 3), confirm the OVP circuit
operates immediately and an external DC voltage
is drop by limiter operation.
5. If OVP circuit is not operate, check up 0901, R913,
R914 and L906.
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