![Yamaha PORTATONE KB-280 Service Manual Download Page 46](http://html.mh-extra.com/html/yamaha/portatone-kb-280/portatone-kb-280_service-manual_896190046.webp)
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5
6
H
G
F
E
D
C
B
A
KB-280
KB-280 BLOCK DIAGRAM
KB-280 BLOCK DIAGRAM
28CA1-2001002836
R+
R+
L+
R+
+
-
R+
R+
R-
R-
L-
R-
L+
L+
A5K
Ω
+V
PB0-PB7
PA4,PA6,PA7,PC6
PA4
POWER AMP
6W X 2
BTL
LA4625
LED
IN
MIDI
OUT
I/F
RXD0
TXD0
PC7
LED
PA6
PA6
PB0-PB5
PB0-PB5
PA6
PB6
AIN4
AIN1
AIN1
AIN1
1PCS
1PCS
1PCS
IRQO
TXDO
RXDO
PC7
IRQ0
PA0
PA0-PA5
PB0-PA7
L
R
8
11
13
14
9
6
1
LED
DGND
AGND
DGND
PA6
PB6
SWL01(T)
128M ROM
PROG./
WAVE
FLASH
ROM
4M
DRAM
4M
ADC
OR
BUFFER/
LPF
MA01-22
MD00-15
MA01-22
MD00-15
MA01-18
MD00-15
MA01-09
MD00-15
RESET
L
R
L
VDD
33
36,38
R
BACK LIGHT
+3.3D
+3.3D
16
16
VCC VCC
fC=27KHz
16.9344MHz
LCD
DISPLAY
PB0-PB7
74LV32A
/UWR, /LWR, /CAS
Crystal SMD-49
+2.5V
+6A
+6A
+6A
74LV138A
74LV138A
LED:2PCS( Blue )
8bit
DAC
LCD
DRIVER
REG3.3V
REG5V
REG2.5V
24bit
+3.3D
+5A
14
2
11
12
5
3
1,2,4
1
7
2,3
8
5,6
9
10
+5D
+5D
+5A
+2.5D
+3.3D
+3.3D
+3.3D
+3.3D
/UCAS
/LCAS
FTolerance
±
100PPM
BCLK
WCLK
BCLK
WCLK
SYSCK
YMW767-VTZ
VCC
36,37
12
37
1,6,22
31,32
8,11
14
7
4
9
1,10
1,2,4
VCC
VCC
+V
PA0-PA7
RS, ENB
RS, ENB
37,121
PA0-PA7
PA0-PA7
PA0-PA7
PB0-PB7
PB0-PB7
LED DRIVER
LED DRIVER
REG6V
12
16
15,46,89,119
24,47,66,90,120
4
VDD
IOVDD
5
13
PF0
LED
LED
LED
LED
+5D
RESET
+3.6V 50ms
B01-B07
B07-B11
SW37-61
SW1-36
PC0-5,PD0-5
PC0-5,PD0-5
TOUCH RESPONSE
Keybord 61KEY (16N)
SD0
PC7
32
40
41
67,68,123
32,34~36
42~44
117
SDI
IC402 (16P)
IC301 (128P)
IC801
(10P)
IC501
(16P)
IC601
(80P)
TR705
TR701~704
IC502(8P)
IC103 (3P)
IC102 (3P)
IC101 (3P)
IC151 (3P)
LD751
LD752
SW771
VR751
SW746~770
LD753
IC551 (14P)
VR551
IC207 (14P)
IC201
(48P)
IC206
(48P)
IC204
(44P)
JK551
JK151
JK852
IC851,TR851,852
JK851
JK853
JK856
SW151
IC401 (16P)
DECODER
CPU
DECODER
B01-B08
B09-B11
PC0-5,PD0-5
PE3-6
IC302 (5P)
X301
DMLCD
CN853 (9P)
CN803 (9P)
CN701 (16P)
CN101 (13P)
CN154 (4P)
CN153 (4P)
CN556 (2P)
CN555 (2P)
CN554 (2P)
CN553 (2P)
CN151 (3P)
CN552 (5P)
CN551 (5P)
CN155 (13P)
CN152 (2P)
CN7855 (3P)
CN777 (3P)
CN776 (6P)
CN775 (6P)
CN772 (7P)
CN773 (7P)
CN774 (16P)
CN703 (16P)
CN771 (16P)
CN5 (7P)
CN2 (5P)
CN1 (12P)
CN4 (12P)
CN3 (12P)
CN402 (7P)
CN401 (12P)
CN403 (5P)
PB
PNL
(AMJK 6/6)
(PN 4/6)
PNL
(PN 2/6)
PNR
(PN 1/6)
PNR
(PN 3/6)
AM
(AMJK 1/6)
( SW 25PCS )
SW MATRIX
SW MATRIX
( SW 39PCS )
SW MATRIX
SW740~745
SW701~739
( SW 6PCS )
61L
(C1~B3)
61H
(C4~C6)
BATTERY
1.5V x 6
PHONES /
OUTPUT
DC IN 12V
AC adaptor
PA-5C/PA-5D/PA-51
SUSTAIN
WOOFER L
TWEETER L
4
Ω
12cm
WOOFER R
4
Ω
12cm
TWEETER R
+
-
+
+
-
-
MASTER
VOLUME
STANDBY/ON
PITCH BEND
TWR
AM
(PN 5/6,6/6)
TWL
(PN 5/6,6/6)
(AMJK 5/6)
MIDI
(AMJK 2/6)
AM
(AMJK 4/6)
EXPRESSION
L
R
Summary of Contents for PORTATONE KB-280
Page 3: ...KB 280 3 SPECIFICATIONS ...
Page 4: ...4 KB 280 PANEL LAYOUT q w 9 0 1 2 3 4 5 e y r t u i Front Panel A A ...
Page 5: ...KB 280 5 032 116 032 116 6 6 8 9 7 u i 6 7 8 9 0 1 2 3 4 o 0 4 5 6 7 8 1 2 3 Rear Panel A A ...
Page 19: ...19 KB 280 DMLCD Circuit Board Pattern side DMLCD 2NA WG23540 ...
Page 29: ...KB 280 29 INITIALIZATION Clr Frash ...
Page 31: ...KB 280 31 MIDI DATA FORMAT ...