Technics RS-TR474 Service Manual page 33

a NI
fo7] ao
S pers
Ver
Deck 1 reel pulse det. input
(take up side)
Deck 1 reel pulse det. input
(supply side)
Deck 2 reel pulse det. input
(take up side)
Deck 2 ree! pulse det. input
(supply side)
Microcomputer terminal
FL meter pull down voltage
input terminal
GND terminal (A/D)
Reference power supply
(+5V) (A/D)
Key switch input
Key switch input
Model selector terminal
Deck 1 Mechanism switch
(FINH, CrO., Metal,
OPEN/CLOSE) input
TRANSISTOR
Q703
collector
| TRANSISTOR
Q704
collector
TRANSISTOR
Q705
collector
TRANSISTOR
Q706
collector
Connector
CN3 @ pin
Connector
CN3 @ pin
Connector
CN3 @ pin
Connector
CN3 @ pin
CN1 © pin
CN2 © pin
10701 © pin
1C701 €& pin
16701 @ pin
Connector
CN1 © pin
Chances within the 0 —
5V range each time the
take up reel on deck 1 is
through approximately
30 degrees.
Supply reel on deck 1
Fast FF/REW mode is disabled unless both
signals 53 and 54 are active. .
Take up ree! on deck 2
Supply reel on deck 2
Fast FF/REW mode is disabled unless both
signals 55 and 56 are active.
+5V, Backup
Can be checked at pin 7 of connector CN801 or
at pin 9 of CN802.
DECK 1:
When no key is pressed: 5V
When Stop key is pressed: 0.4V
When Power key is pressed: 0V
When any other key is pressed: 0 to 5V
DECK 2:
When no key is pressed: 5V
When Stop key is pressed: 0.4V
When any other key is pressed: 0 to 5V
Change the voltage at this pin to match
microprocessor operation to the individual
model.
TR474: Approx. 1.2V
No tape loaded: Approx. 4.1V
Normal tape with tab: Approx. 2.3V
Chrome tape with tab: Approx. 3.5V
Metal tape with tab: Approx. 3.5V