Sony XR-1790 (serv.man2) Service Manual ▷ View online
XR-1790
17
17
5-4.
SCHEMATIC DIAGRAM – MAIN Board (2/2) –
•
See page 19 for IC Block Diagram.
(Page 18)
XR-1790
18
18
5-5.
PRINTED WIRING BOARD – CONTROL Board –
5-6.
SCHEMATIC DIAGRAM – CONTROL Board –
• Semiconductor
Location
Ref. No.
Location
D4
B-9
D900
C-10
D901
C-7
D902
C-6
D903
C-8
IC900
B-9
• Waveform
2
IC900
es
(OSC)
2.2 Vp-p
15
µ
s
(Page 15)
(Page 17)
19
• IC Block Diagram
– MAIN Board –
– MAIN Board –
IC450
LC75372E
2
1
4
3
6
5
8
7
10
9
12
11
14
13
16
15
15
43
44
41
42
39
40
37
38
35
36
33
34
23
24
25
26
19
20
21
22
29
30
31
32
27
28
17
18
DECODER
LATCH
CONTROL
SHIFT
REGISTER
ROUT
RFIN
RFOUT
RROUT
RVREF
VREF
LVREF
LROUT
LFOUT
LFIN
LOUT
R2
R1
TEST
VSS
NC
CL
DI
CE
L2
VDD
L1
LT3
LT2
L10dBOUT
LT1
LIN
LCT2
LCT1
L10dBIN
LSELO
L3
NC
RT3
RT2
RT1
RIN
R10dBOUT
RCT2
RCT1
R10dBIN
RSELO
NC
R3
+
–
–
+
–
–
+
–
–
+
–
LVREF
LVREF
RVREF
LVREF
LVREF
LVREF
LVREF
LVREF
LVREF
+
–
+
–
+
–
+
–
+
–
+
–
–
RVREF
RVREF
RVREF
RVREF
RVREF
RVREF
RVREF
+
–
–
+
–
–
+
–
–
+
–
–
20
5-7.
IC PIN FUNCTION DESCRIPTION
•
MAIN BOARD IC1 LC72322N-9538 (SYSTEM CONTROLLER)
Pin No.
Pin Name
I/O
Description
1
XIN
I
System clock input terminal (4.5 MHz)
2
TEST2
I
Connected to ground
3
NC
I
Not used (fixed at “H”)
4
AM-SD
I
AM signal meter voltage detection input from the FM/AM tuner unit (TU100) “H” active
5
FM-SD
I
FM signal meter voltage detection input from the FM/AM tuner unit (TU100) “H” active
6
STEREO
I
Stereo detection signal input from the FM/AM tuner unit (TU100) (Commonly used for stereo
display input) FM stereo detection at input of “L”
display input) FM stereo detection at input of “L”
7
MOTOR
O
Capstan/reel motor (M901) drive signal output “H”: motor on
8
AMP-MUTE2
O
Muting control signal output to the power amplifier (IC500) “L”: muting on
9
MW/SW
O
MW/SW selection signal output terminal “L”: SW, “H”: MW Not used
10
—
O
Not used (open)
11
BEEP
O
Beep sound signal output terminal “H” active
12
POWER-ON
O
Power on/off control signal output “H”: power on
13
ILL-ON
O
Power on/off control signal output for the liquid crystal display driver (IC900), illumination lamp
and back light lamp “H”: power on
and back light lamp “H”: power on
14
N/R
I
Tape direction switch (S901) input terminal “L”: forward side, “H”: reverse side
15
TAPE-IN
I
Tape in detection switch (S903) input terminal “L”: tape in
16
FF-REW
I
FF/REW detection switch (S902) input terminal “L”: FF/REW mode
17
K1
I
Key matrix return signal input terminal Not used (fixed at “L”)
18
K0
I
Key matrix return signal input terminal (Connected to T2 (pin wg))
19
AMP-ON
O
Standby on/off signal output to the power amplifier (IC500) “L”: standby, “H”: amp on
20
SEEK
O
Seek control signal output to the FM/AM tuner unit (TU100) “H” active
21
SEEK
O
Seek control signal output terminal “L” active Not used (open)
22
LOCAL/DX
O
Local/DX selection signal output to the FM/AM tuner unit (TU100) “L”: DX, “H”: local
23, 24
—
O
Not used (open)
25
T2
O
Key matrix scan signal output terminal (Connected to K0 (pin qk))
26
T1
O
27
T0
O
28
VOL-CE
O
Chip enable signal output to the electrical volume (IC450) “H” active
29
VOL-DI
O
Serial data output to the electrical volume (IC450) “H” active
30
VOL-CL
O
Serial data transfer clock signal output to the electrical volume (IC450)
31
VDD
—
Power supply terminal (+5V)
32
MUTE-REQ
I
Muting request signal input terminal (“H” active) “L”: accessory on, “H”: accessory off
33
BAND-KEY
I
A MEM TUNER switch (S900) input terminal “L” is input when pressing the switch
34
PANEL-IN
I
Detects the removal of the attaching and removing type front panel block “L”: attaching
Not used (connected to pin es)
Not used (connected to pin es)
35
NC
I
Not used (fixed at “L”)
36 to 40
—
O
Not used (open)
41
MUTE
O
Audio muting on/off control signal output terminal “H”: muting on Not used (open)
42
—
O
Not used (open)
43
AMP-MUTE
O
Amp muting on/off control signal output terminal “L”: muting on Not used (open)
44
ANT-REM
O
Control signal output for the external power antenna and external amplifier “H” active
45 to 48
—
O
Not used (open)
49 to 51
KS2 to KS0
O
Key matrix scan signal output terminal
52
—
O
Not used (open)
53
LCD-CLK
O
Serial data transfer clock signal output to the liquid crystal display driver (IC900)
Key matrix scan signal output terminal Not used (open)
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