Main Board; Display Board - Sony STR-K990 Service Manual

– MAIN Board –
IC501, IC601, IC701 uPC2581V-S
BIAS CIRCUIT
PROTECTOR
PRE
REG DRIVE
DRIVE
2 3 4 5 6
1 7
– DISPLAY Board –
IC100 PT6315
LED1
1
LED2 2
3
LED3
LED4
4
OSC
5 OSC
DOUT
6
DIN
7
Serial
interface
CLK
8
STB
9
KEY1
10
KEY2 11
12 13
PRE
DRIVE
DRIVE
8 9 10 11 12 13 14 15
44 43 42 41 40
Grid driver
Command decoder
Display memory
24 bits x 12 words
Timing generator
key scan
Key data memory
(2 x 16 bits)
– DISPLAY Board –
IC101 TC74ACT08P
8
7
39 38 37 36
Multiplexed driver
segment driver
14 15 16 17 18 19
STR-K990
9 10 11 12 13 14
6 5 4 3 2 1
35 34
SEG19/GRID10
33
32 SEG18/GRID11
31 SEG17/GRID12
30 VEE
SEG16/KS16
29
28 SEG15/KS15
27 SEG14/KS14
SEG13/KS13
26
SEG12/KS12
25
SEG11/KS11
24
SEG10/KS10
23
20 21 22
41