Kenwood TM-281A Service Manual page 39

P
TX-RX UNIT (X57-8130-XX)(B/2) : DISPLAY SECTION
INT SP
+
SPOUT
-
SPGND
ENCODER
D901
W02-3704-05
REVERSE
C901
CONNECTION
PROTECTIOM
0.1u
D901
R901
0
1SS355
SURGE
7.56V
J901
ABSORPTION
8
CM
HOOK
MIC
ME
PTT
GND
8C
MBL(Key A)
1
CN901
SPGND
1
SPGND
2
SPOUT
3
SPOUT
4
8C
5
RXD
6
PTT
7
VOL
8
MICKEY
9
5C
10
CM
11
ENCA
12
ENCB
13
DI
14
DO
15
CE
16
CL
17
BRI
18
POWER
19
MIC
20
ME
21
GND
22
Note: The components marked with a dot (
Q
SCHEMATIC DIAGRAM
MR VFO CALL
S901
REV Func
R902
4.7k
R903
4.7k
4.96V
VR901
R908
R31-0662-05
100
VARIABLE
RESISTOR
CP901
1k x4
5.00V
L901
5.00V
R912
R910 R911
10k
10k 10k
KEY BACKLIGHT SWITCH
KEY ILLUMINATION
Q901
D903 D904
RT1P141U-T111
R914
1k
D905
R915
1.5k
D903-905
B30-2337-05
LED
Q902
RT1N141U-T111
DC SWITCH
•
) are parts of layer 1.
R
LCD
49
NC
50
KI1
51
KI2
52
KI3
53
NC
54
NC
55
NC
LCD DRIVER
56
VDD
IC901
57
PT6554LQ
VDD1
58
VDD2
59
VSS
60
OSC
61
DO (to cpu)
62
CE
63
CL
64
DI (from cpu)
LCD BACKLIGHT SWITCH
7.81V
Q903
2SB1132(Q,R)
BRIGHTNESS
FUNCTION Q904
SWITCH
UMG3N
R909
1k
S
TM-281A
32
SEG27
31
SEG26
30
SEG25
29
SEG24
28
SEG23
27
SEG22
26
SEG20
25
SEG20
24
SEG19
23
SEG18
22
SEG17
21
SEG16
20
SEG15
19
SEG14
18
SEG13
17
SEG12
LCD ILLUMINATION
D906 D907
R922
330 B30-2337-05
B30-2337-05
D908 D909
R923
330 B30-2337-05
B30-2337-05
D910
D911
R924
330
B30-2337-05 B30-2337-05
D906-911
LED
X57-813 (B/2) 1/1
T
1
2
3
4
5
6
7
39