4-1
S MIC Chassis
SECTION 4
SAFETY RELATED ADJUSTMENTS
Note: The “4-1. B
++
++
+ Voltage Check” and “4-2.
Protection Circuit (Hold-down circuit) Check”
should always be performed when replacing
the following components marked with and
on the schematic diagram.
D board
components......RV833, RV1603
components......C519, C843, C844, C845, C846, C847,
C848, C1601, C1602, D835, D836,
D1601, D1603, IC502, Q833, Q834,
Q835, Q836, Q1601, Q1602, Q1603,
R523, R850, R851, R852, R853, R854,
R855, R856, R857, R858, R859, R860,
R861, R862, R863, R1601, R1602,
R1603, R1604, R1605, R1606, R1607,
R1608, R1628, R1629, R1630, RV833,
RV1601, RV1603
G board
components......RV651
components......C654, IC601, IC651, PH601, R653,
R655, R656, R657, RV651
P board
components......C814, NL801, T802 (FBT)
4-1. B
++
++
+ VOLTAGE CHECK
4-1-1. B
++
++
+ Voltage Check in AC Operation
Note: Be sure to use the NF power supply. If not, use
an ordinary variable step-up transformer of its
distortion factor is 3 % or less.
Input signal: Dot pattern signal
Controls: BRIGHT 8 Minimum
CONTR 8 Minimum
1. Input 130
+5
Vac from the NF power supply (or
_0
variable step-up transformer of its distortion factor is 3 %
or less).
2. Connect the digital voltmeter to pin 6 of RY1601 and
ground on the D board.
3. Make sure that the voltage is within the following
specification.
Specification:
RY1601 Pin-6 (D board) = 41.9 Vdc or less
4. If the above voltage is out of specification, adjust
voltage with RV651 on the G board. After adjusting, be
sure to apply paint to RV651.
RV833
RV1601
8 CN503
A
+
4-2-2
0.1 uF
100 V
TO P BOARD
CN801-8
+
_
DC
POWER
SUPPLY
6
RY1601
L1602
TP85
4-2-24-1-1
DVM
_
++
_
DVM
4-1-2
C1605
_
+
4-2-1
SUPPLY
POWER
DC
9.4 Vdc
_0
+0.1
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