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ST-H2750/H3750
|
1-1.
SUPPLY OF POWER DURING SERVICES
+ Frequencies initially preset
-
FM
l
87.5MHz
o30kHz
- 531kHz
2
88.0MHz
620kHz
621kHz
3
98.0MHz
1050kHz
1053kHz
4
100.0MHz
1490kHz
1485kHz
i)
108.0MHz
1710kHz
1710kHz
2
*1
The same frequency values are set for the preset
memory No. 6—No.10, No. 11—No. 15 and No. 16
—No. 20 as for No. 1—No. 5 respectively.
*2
The same frequency values are set for the preset
memory No. 6—No. 10 as for No. 1—No. 5.
SECTION
1
SERVICING NOTES
Because the equipment is not provided with any power sup-
ply, it is operated with power supplied from the amplifier
DX A-H2750/H3750 used in the series. The equipment requir-
es the following 4 types of voltages. Therefore, connect the
equipment to
DX A-H2750/H3750 for services such as repair-
ing with power supplied, because it will be too complicated to
supply these voltages individually.
VOLTAGE
MAJOR CIRCUIT IN USE
AC 3.9V
FL tube filament voltage (VF)
DC —24V_
| Display controller IC701 grid voltage (VG)
DC 5.6V
Display controller IC701, Tuner
PLL
IC81
Vec
DC 12V
Tuner RF, FM/AM DET IC21 Vcc
1-2.
SERVICE MODE TO CHECK TIMER ON-OFF
It is possible to check whether the timer normally functions
while being connected with an amplifier.
(1) Connect
the equipment
to the amplifier
DXA-H2750/
H3750 and set the SYSTEM POWER switch to STAND-
BY state.
(2) Set the time of the tuner to any time.
(3) Press 3 switches "BAND", "—" and "MEMORY/NEXT"
at the same
time
(while pressing
"BAND"
and "—"
beforehand, finally press "MEMORY/NEXT")
(4) FL display tube
10; 21
10: 22°
<_ <_ S S en wn DQ Q
MD oD Q Q
10: 23
10: 24
— POWER ON
<_ <— ead
S on on Q Q
a2) oD Q Q
FUNCTION:
CD
.
1 3sec
0:
00
— POWER OFF
(5)
Completion
Note: After completion of the checking above, data preset in
the memory IC702 is erased while resetting the mem-
ory to the next page state upon shipping from the
works, so be sure to recover
the same
frequency
as
that before the repairing.
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