Akai AAA 25 AAA 25 L Service Manual

Page 2

, ABBREVIATION

, EXPLANATIONA '-

AC
A/D.
AFC,

, AGC
ALC , .
AM
ANT
A-s'w"
BUF
CK
WA
DC,
DET

FLD (FL DISPLAY)

FM
FREQ
GND

1F '

A, :DETeetor

Alternating Current
Analog/Digital

, Auto Frequency Control: _

Auto Gain Control
Auto Level Control

'1 Amplitude Modulation 1,: A
ANTenna A
Analog SWitch

BUFfur
ClocK '
D1g1tal/ Analog

Direct Current

Flip Flop
FLuoreseent Display

Frequency Modulation '
I FREQuency
GrouND L

Intermediate Frequency,

Page 32

A1007A

:3. Functions 11:}: Functions
.1 DIGIT 0 29 CARTRIDGE (MM/MC) SELECTION INPUT
2 DIGIT 1 STROBE FOR KEY MC -> H MM -> L
3 DIGIT 2 MATRIX CONVERTER 30 TEST
4 DIGIT 3 31 XIN
5 DIGIT 4 FL DISPLAY 32 XOUT
6 DIGIT 5 33 RESET INPUT
7 SEG 12 34 HOLD INPUT (BACK UP)
8 SEG 13 35 INPUT STATUS OUTPUT, TUNER -> L
199 SEG 11 FL DISPLAY PHONO/CD -> H
10 SEG 10 SEGMENT DRIVE 36 TUNER OPERATION PULSE INPUT,
11 SEG 9 Switching input selector to TUNER whenever
12 SEG 8 receives the pulse (6 m sec) from Tuner
13 INPUT SELECTOR MI-COM (IC A1007T)
'DATA FOR ANALOGUE SW 37 MM/MC CIRCUIT SWITCHING OUTPUT.
14 INPUT SELECTOR 38 DATA DETECTION FROM A/D
CLOCK FOR ANALOGUE SW CONVERTER
15 INPUT SELECTOR 39 END DETECTION FROM A/D
STROBE FOR ANALOGUE SW CONVERTER
16 STROBE FOR ELECTRONIC VOLUME 40 ST-WR (CONVERSION START)
(MAIN, BASS, TREBLE VOLUME) OUTPUT FOR A/D CONVERTER
17 SEC 7 (LC-7910)
18 SEG 6 FL DISPLAY DATA OUTPUT FOR MAIN, BASS, TREBLE
19 SEG 5 SEGMENT DRIVE CONTROL VOLUME IC (TC9176P,
» 20 SEG 4 TC9156P x 2)
721 GND 41 CE (DATA CLOCK) OUTPUT FOR
22 SEG 3 A/D CONVERTER (LC7910)
23 SEG 2 FL DISPLAY CLOCK OUTPUT FOR MAIN, BASS
24 SEG 1 SEGMENT DRIVE TREBLE, CONTROL VOLUME IC (IC9176P,
25 SEG 0 TC9150P x 2)
26 42 VDD +5V
27 KEY MATRIX INPUT
28