Teac A-7300RX - Troubleshooting

28
11. TROUBLE-SHOOTING-1
MALFUNCTION
—
Pilot
Lamps
(in
VU
Meters)
do
not
illuminate
when
power
is
applied
......-..-....---000-
_—
Fuse
burns
out
(blows)
when
power
is
applied
.....
—Capstan will not rotate .......-......-.00..
—
Transport
inoperative
in
Forward
Playback
.......
—
Pinch
roller
fails
to
engage
completely
..........
— Right Reel Motor does not rotate .............
—
Neither
Reel
Motor
rotates........-..-...0-.
—
Fast
Forward
or
Rewind
modes
inoperative
(Playback
isOK)
......--.---
see
eee
ee
eeee
POSSIBLE SOURCE OF TROUBLE
Fuse F701 (2A) burned out
Defective Power transformer (T151)
Specified 24V DC present on the CAPSTAN MOTOR ASS’Y
J152 Pins #1~7 :
Defective CAPSTAN MOTOR ASS’Y
Specified 24V DC not present on the STABILIZER UNIT
J21 Pins #11, #12
Defective STABILIZER UNIT ASS’Y or Connector loose
Specified 37V DC not present on the STABILIZER UNIT
J21 Pins #13, #14
Defective D1O~D13 or Power transformer (T151)
Faulty Safety switch (SW156)
Voltage present on the CAP SOL. 1 terminals
CAP SOL. 1 Disconnected
High-Level voltage (approx. 3V) present on the SOLENOID
DRIVE UNIT J121 Pin #3
Defective Q121 or Q122
High-Level output voltage not present on the CONTROL
UNIT P41 Pin #1
Defective CONTROL UNIT
Fast Forward OK ..... Defective Q71 or Ki2
High-Level output voltage not present on the CONTROL
UNIT P41 Pins #1 or #2
Defective CONTROL UNIT
High-Level output voltage present on the REEL MOTOR
DRIVE UNIT at H terminal
Defective Reel Motor
Brakes not dis-engaged
Disconnected brake Solenoid R or L,
Defective Q125 or Q126
High-Level output voltage present on the SOLENOID
DRIVE UNIT J121 Pin #8
Defective SOLENOID DRIVE UNIT
High-Level output voltage not present on the CONTROL
UNIT P41 Pin #2
Defective CONTROL UNIT
High-Level output voltage not present on the CONTROL
UNIT P41 Pins #4,#7
Defective CONTROL UNIT "
High-Level output voltage present on the CONTROL UNIT
P41 Pin #2
Defective SOLENOID DRIVE UNIT (Q135, Q126)
NOTE:
Explanation
of
abbreviations
and
circuit
component
designations.
F
...
Fuse
D...
li
ode
SW
...
Switch
K...Relay
T...
Transformer
J...
Pin
jack
(Female)
Connector
?
...
Pin
plug
(male)
connector.
High-Level
output
voltage-
Logic
true
level
approx.
+3V.
Refer
to
the
circuit
diagram
for
further
assistance
in
locating
possible
defective
circuit
:om-
ponents.