Akai M-10

SECTION
“B"'
TROUBLES
WITH
AMPLIFIER
1. Playback Mode
No
sound
from
Internal
Normal
sound
when
connected_jaternal
Speaker
Defective
Repl Speak
Speaker
to
External
Speaker
eplace
speaker
N
und
wh
ted
Transistor
TR
1,
TR
2,
t
vEXt
‘
i
See
ie
&¢__
or
TR
501
or
TR
502.
—————
Replace
transistor
Spee
eae
ole
defective
Distorted
sound
from
Normal
sound
when
connected
Internal
Speaker
~
External
Speaker
Intenal
Speaker
Defective
Replace
Speaker
Sound
distorted
when
é
connected
to
External
Transistor
ER
USO}
OE
5
it
aoa
Replace
transistor
Speaker
TR
502
defective
Improper adjustment ‘
of VR $01 or VR 50277 Re adjust
Sound from left and right
speakers unbalanced even
when volume controls are
set to Maximum
Improper adjustment of Main Amplifier
Level Control Potentiometer VR 601. = —————— Re-adjust
(20 K 2 B)
Diode D401 or transistor (TR401) 2SD223
ine- + 1 —
No
sound
from
Line-Out
Jack
[
No
B
(+)
Voltage
Supply
defective
Replace
Transi TR104
—
B
(+)
Voltage
Supply
present
Mute
Relay
is
operating
—
ee
CERIO
)_
Replace
Check working order of Transistor TR101,
TR102 and IC101
Broken wire within Playback Head Coil or
broken Lead Wire
Will
play
back,
but
volume
B
(+)
Voltage
low
—___—_—____
Diode
D401
or
Transistor
(TR401)
defective
—
Replace
insufficient |
B
(+)
Voltage
normal
—————————
Ox
ide
has
accumulated
on
the
Head
—---———
Clean
Head
Humming
noise
When
Playback
Head
grounded
Hum
backing
coil
adjustment
faulty
————-—
Re-adjust
noise decreases
L, en circuit Playback Head Coil Replies:
Pp y Playback Head
Grounding Playback Head does Power Supply Circuit Transistor (TR401) R
=—— , — Replac:
not alter hum defective
Oxide has accumulated on
Playback Head
Sound
distorted
Clean
Head
io
Check to see if B (+) Voltage is In case B (+) Voltage is low, check D401
normal and TR401
In case B (+) Voltage is normal,
check voltage of preamplifier parts
When tape is running,
hissing noise increases
Hissing
Noise
Head
is
magnetized
Demagiet
ize
Head
Tape itself noisy
Replace Tape
Replac
cuit’? :
Open Circuit Playback Head Coil Pisy bem Head
Irregular Scratching or Transistor TR101 or TR102 Reédiace transistor
Cracking
Noise
|
defective
Pp
Resistor R104, R105 or R107 Replace Resistor
defective
é . Oxide collected on surface of
—— Clean H
Squeaking
Noise
oe
Head
an
Head
Tape itself squeaks -———————— Replace Tape
a
29