akira CT-21XF9, Service Manual

Page: 28 / 77

28
Model No: CT-21XF9A
Version 1.0
Table 3 Pin functions and repair data of TB1238AN
Index type multimeter (r=20k )
Resistance for GND
(RxlK)
Pin Symbol Function
'Quiescent
state
(V)
Dynamic
state
(V)
Red pen
measure
Black
pen
measure
1 DE-EMP Audio deemphasis
capacitor connect pin
5 4.9 7.2 9.0
2 AUDIO OUT Audio signal output 3.5 3.4 6.5 7.3
3 IF VCC +9V supply input for IF
amplify circuit
9 9 0.8 0.8
4 AFT OUT AFT voltage output 2 1.7 6.2 8.3
5 IF GND Ground for IF amplifier
circuit
0 0 0 0
6 IF IN IF signal input 0.20 0 6.8 11.2
7 IF IN IF signal input 1.4 1.4 6.8 11.2
8 RF AGC RF amplifier AGC
control voltage output
7.2 5.6 7 10
9 IF AGC IF amplifier AGC filter 6 4.4 7.2 11.2
10 APC FILTER APC filtering 1.8 1.8 10 11.2
11 4.43MHZXTA 4.43MHZ crystal
oscillating
2.2 2.2 7.4 120
12 Y/C GND Ground (Y/C signal
processor) 0 0 0 0
13 YS/YM Y-switch signal input 0 0 1 2
14 EXT R IN Character R signal input 0.9 0.9 7.2 11.2
15 EXT G IN Character G signal input 0.9 0.9 7.2 11.2
16 EXT B IN Character B signal input 0.9 0.9 7.2 11.2
17 RGB VCC Supply input (RGB) 9 9 0.8 0.9
18 R OUT R output 2.1 2.4 7 10
19 G OUT G output 2 2.4 6.8 10
20 B OUT B output 2.2 2.5 6.8 10
21 ABCL automatic brightness,
contrast control 5.3 5.4 7.4 11
22 V Ramp vertical Ramp generator
capacitor connect pin
5.4 4.4 7 11
23 V NFB V NFB input 5 5 7 9.3
24 V OUT vertical pulse signal
output
1 1 1 1
25 V AGC V AGC filter capacitor
connect pin
0.2 0.3 7.2 18
26 SCL (I2C) clock line 3.8 3.8 6 18.1
27 SDA (I2C) data line 3.8 3.9 6 18.1