Teac A-7300 - Page 16

TROUBLESHOOTING
eee
POSTAL
SoU
Teouace
-MALFUNCTIOI
PPPOE EES
Transport inoperative
(Capstan
only
rotates)......-eeeeeee
ea
acgracanebieteces
..Specified
8V
DC
present
on
the
STABILIZER UNIT J21 Pins #5, #6
ln Defective STABILIZER UNIT
Specified 8V DC not present on the
STABILIZER UNIT J21 Pins #5, #6
Lerouley D14~D17 or fuse F2 (2A)
Cannot
select
PAUSE...
.ccecec
cence
eeececeeesesess
Defective
CONTROL
UNIT
....Voltage not present on P151 at Pin #10
or #11 (To ampl. connector)
lease Fl (2A),F4 (0.5A) burned out
Amplifier inoperative......... Dfelieve.S Stace leveré ae
Voltage present on P151 at Pins
#10 or #11
Lonetkeeave Q601, Q602, Q603
(on AMPL. STABILIZER UNIT)
Playback audio intermittent or absent
a)
Both
channels
inoperative..........
seagate
reset
sce
...-Defective
Q207,
Q208,
Q209
or
associated
parts
(SOURCE
OK)
b)
Roch
or
L-Ch
inoperative.......++eseeeeeee
...-SOURCE
also
inoperative
|
Defective
Q301
or
associated
parts
SOURCE Monitor function normal
Defective Q201, Q203, Q205, Q207, Q251, Q253,
Q255 or associated parts
Playback
sound
is
not
clear........+..+++++e+5++--High
Freq.
weak.....Dirty
head,
incorrect
Adj
of
VR201/203
Sound distorted.....Defective Q201, 203, 205
-
VU
Meter
inoperative
in
TAPE
Monitor
mode........Defective
Q306
or
associated
parts,
(sound
is
normal)
Faulty
VU
Meter
ass'y
-
Hum
in
playback
signal........-.eeereeeeees
.....-Defective
Playback
head
- Intermittent or absence of audio
at
PHONES
jack...
ccc
ccc
cece
eee
ee
ese
wceeee
weeeeeee
Defective
Q303,
Q305
Q307
or
associated
parts
-
LINE
IN
signal
is
not
applied
to
SOURCE..........Defective
Q405,
Q406,
Q451,
Q453...etc
(Playback
normal)
—
WL11
not
Record.
...ccee
cc
cccccr
ence
recsessces
...-No
Erase.....Defective
K551,
Q551™~
554,
1T551
leaspecink
normal..
.++.-Sound normal at SOURCE
Lnefective Q507, Q509,
Dirty or defective recori head
-
Recorded
sound
not
clear.
...
cece
ces
ee
cece
eeenee
.Dirty
record
head,
incorrect
Bias
Adj.
or
-
Inoperative
MIC
Recording
Detective,
Oy?
(LINE
IN
signal
normal)
.......eseeee
eee
eeeeees
.
Defective
Q401~Q404....etc
~
Hum
in
Recording
signal........-..sseeee-
weeeee.-Defective
Record
head
or
P702
connector
loose
or
heads
magnetized
Note:
Explanation
of
abbreviations
and
circuit
component
designations.
F...Fuse
D...Diode
SW...Switch
K...Relay
T...Transformer
J...Pin
jack
(Female)
Connector
P...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
components.
15