Akai 1710W

X. TROUBLE SHOOTING CHART
SECTION
“A”
TROUBLES
WITH
AMPLIFIER
A.
Piayback
problems.
(Unit
set
in
play
position.)
1.
No
sound
from
loud
speaker.
--| Fuse blown
Defective power
transformer.
Vacuum tube(s)
does not light.
i Check and replace. |
Defective switch }-—— Check and replace. |
Hum from loud
Vacuum tube(s) r
seems okay. speaker. Head coil burned out. Check and replace.
Defective top or 2nd stage
Lo !
transistor (TR1, TR2| -—— Replace.
Defective Rec/Play changing See et ee
"|
switch
Pl,
J601
|
———tis
and
replace.
Lf
No speaker hum.
|S Speaker voice coil bumed out.
t— Defecive power output tube. (6CA4)
2. Sound from speaker but insufficient volume.
Defective TR1, TR2
Replace
Dirty head surface
Recording tape being reversed.
No change after transistor
replaced.
B (+) voltage low.
Output transformer bumed out. |---| Check and replace |
Clean heads gently with cotton swab
soaked in rubbing alcohol.
Check and correct tape.
Check Tube (6CA4), C19, C18, R23.
Defective resistor(s) and/or
capacitors) in circuit.
ald
3. Sound from speaker but with loud hum.
a,
=
voltages,
and
replace
defective
one(s)
Hum
controllable
with
volume
control.
t—
Defective
TR1
or
TR2
-
Replace TR1 or TR2.
[Head TR1,TR2, ground wire improperly positioned [—{ Dress ground wire. |
Hum not controllable with volume
Defective V1, V2
control.
[Hum reduced when playback head
shorted.
t—
t{ Hum bucking coil out of adjustment, |__|
Leakage flux from motor or from power transformer. 1,
Replace V1, V2
— Defective C16, R21 or C18, cig /}_____ Replace
7;
Shielding
on
playback
head
not
perfect.
-——
Replace
head.
Check motor and power transforme
replace if necessary.
‘
Read just hum bucking coil |
Unit picks up external magnetic flux.
Ground recorder at capstan storage post.
Hum only when play.
: Mg. ADP, Hum recorded on tape. }—
no hum without tape.
|
Reposition recorder.
Shield recorder.