Olivetti d-Copia 1600, Service Manual

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2HA/2HB
2-3-14
2-3-4 Operation unit PWB
Figure 2-3-7 Operation unit PWB block diagram
The operation unit PWB (OPWB) consists of key switches, LEDs, 7 segment LED and buzzer. The lighting of LEDs is
determined by scan signals (SCAN0 to SCAN7) and LED lighting selection signals (LED0 to LED12) from the main PWB
(MPWB). The key switches operated are identified by the scan signals (SCAN0 to SCAN7) and the return signals (KEY0
to KEY4).
K5 K10 K15 K20 K25 K30 K39 K38
K4 K9 K14 K19 K24 K29 K37 K34
K3 K8 K13 K18 K23 K28 K36 K33
K2 K7 K12 K17 K22 K27 K32
K1 K6
D1
+5V
+5V
BUZERDRN
SCAN7N
SCAN6N
SCAN5N
SCAN4N
SCAN3N
SCAN2N
SCAN1N
SCAN0N
10
9
8
7
6
5
4
3
2
1
f1
f2
f3
g1
g2
g3
DP1
DP2
DP3
Dig1
Dig1
Dig2
Dig3
27
23
17
28
22
12
5
9
14
3
26
19
18
e3
e2
e1
d3
d2
d1
c3
c2
c1
b3
b2
b1
a3
a2
a1
10
6
1
11
7
2
13
8
4
15
20
24
16
21
25
KEY4
KEY3
KEY2
KEY1
KEY0
LED12
LED11
LED10
LED9
LED8
LED7
LED6
LED5
LED4
LED3
LED2
LED1
LED0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
BZ1
YC1
U1
SW
LED
7 segment YC2
2
1
K11 K16 K21 K26 K35 K31
D2
2
1
D3
2
1
D4
2
1
D5
2
1
D6
2
1
D7
2
1
D8
2
1
L9 L18 L27 L36 L46
L37 L75 L76
L55 L64 L73
L8 L17 L26 L35 L45 L54 L63 L72
L7 L16 L25 L34 L44 L53 L62 L71
L6 L15 L24 L33 L43 L52 L61 L70
L5 L14 L23 L32 L42 L51 L60 L69
L13 L22 L31 L41 L50 L59 L68
L3 L12 L21 L30 L40 L49 L58 L67
L2 L11 L20 L29 L39 L48 L66
L1 L10 L19 L28 L38 L47 L56 L65
L74