PVM-6041QM I
SECTION 4
SAFETY RELATED ADJUSTMENTS
4-1. SAFETY RELATED ADJUSTMENTS
B+ ADJUSTMENT AND B+ MAX CHECK FOR SERVICING
( B RV651)
Thefollowingadjustmentsshou!dalwaysbeperformedwhenreplacing
thefollowingcomponents(markedwith
[.j ontheschematicdiagram).
CiiilonGboard: (Power supply block)
JC601, IC651, PH601, C654, R653, R655, R656, R657, RV65L
I. Input the AC power supply voltage 240V:c\V.
2. Inputthemonoscopesignal.
3. Setasfollows.
• CONTRAST ............. 80%
• BRIGHTNESS. . .... 50%
4.
Connect the digital multimetertoRY1601pm.Q)on theD board.
5. AdjustRV651 ontheG
boardsothatthe+Bvo!tagebecomes40.0
±0.IV.
6. After adjusting RV651, fix
it with an epox};-
7.
Input the AC power supply voltage 240V --0 V.
8. lnputthedotsignal
9. Setasfollows.
• CONTRAST
.. . ....... Minimum
• BRIGHTNESS .......... Minimum
10. Check that the B+voltage is below 41.9V.
Ifitisabovethisvalue,repeatfromstepj_
B+ MAX IN DC POWER INPUT MODE, CONFIRMATION
( B RV1603)
The following adjustments should always be performed when replacing
the following components (marked with
1:iiiil on theschematicdiagram).
1:iiiil onDboard:
Q1601,Q1602,Q1603,Dl60!,Dl602,Dl603,Dl604,Dl605,Cl601,
C1602, RJ601, R1602, Ri603, Rl604, R 1605, Rl606, R 1607, Ri608,
R1629, R1628, R1630, RVI601, RV1603.
1. Supply DC
12v~g
4
VfromDC 12V IN connector.
2. Receiveadotsignal.
3. • CONTRAST ... . ........ Minimum
• BRIGHTNESS .......... Minimum
4. Connect a digital multimeter to C1605
positive+ sideofD board.
5. Turn RV1601 on the D OOard fully clockwise. Confirm that the
voltage ofC1605 + pin is Jess
thfill 41.9V DC.
6. If step
5 is not satisfied, readjust the RV1603. After adjusting,
fastenRV1603inplacewithepoxy.
HOLD-OOWNCIRCUITCONFIRMATION(
8 R~833),AND
READJUSTMENTS
The following adjustments should always be performed when replacing
thefo!lowingcomponents (marked with c,j on the schematic diagram).
1:iiiil onDboard:
IC502, Q833, Q834, Q835, Q836, D835, D836, C519, C843, C844,
C845, C846, C847, C848, RV833, R523, R850, R851, R852, R853,
R854, R855, R856, R857, R858, R859, R861, R862, R863.
1:iiiil on P board:NL801,T802 (FBT),C814.
1. Receiveanentirewh1tesignal.
2. • CONTRAST... ... . ... Maximum
• BRIGHTNESS ............ Maximum
3. Connect
a digital multimeter to the TP85 (CN503 pin·®).
4. Confirm the voltage is 14.1 ± 3.0V DC.
5. Receiveadotsignal.
6. Connect an ammeter between D board CN503 pin·® andPboard
CN80lpin-@.
7. Adjust BRIGHTNESS and CONTRAST so that the current
is
IABL = 160 ± 30 µA.
8. Apply an external DC voltage gradually to TP85. When the
voltage becomes 18.SV
± 0.1 V DC, confirm the HOLD-DOWN
circuitoperatesimmediatelyandrasterdisappears.
9 When external DC voltageatTP85 becomes 17.SV ±0.lV DC,
confirm the HOLD-DOWN circuit doesn't operate.
10. Receiveanentirewhites1gnal.
J 1. Adjust with BRIGHTNESS and CONTRAST controls so that the
current is IABL
= 520 ± 30 µA.
12. ApplyDCvoltageof\7.8V± O.lV toTP85.ConfirmtheHOLD-
DOWN circuit
operates immediately and raster disappears.
13. With the same set-up as steps
JO and I !,supply 16.8V± O.IVDC
to TP85. Confirm that the HOLD-DOWN circuit doesn't operate.
14. When
above specifications are not satisfied, readjust RV833.
After adjusting, fasten RV833 in place with epoxy.
-18-
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