Denon DN-790R - Page 16

DN-7gOR
I
4-2
Adjustment
of tilt
angle
(l)
Set THG-801
(jig
board)
in
the
mechanical
unit
and
place
THG-801
(jig
shaft)
on the
recording
head
to
inspect
the
gap
between
the
jig
board.
lf
the
jig
shaft is
tilted
forward,
the
tilt
screw
@
l.
too
tight.
Loosen
it
stightly
and
adjust
the
tilt
screw
(7D)
until
the
jig
stick
is
parallel
to
the
jig
board
and the gap
is
completely
eliminated.
(2)
Readjusting
the
tilt
may
cause
the height
adjustment
to
stip.
After
adjusting
the
tilt,
be
sure to
verify
the
height.
lf
the height
is
misaligned,
turn
the
special
height
adjustment
r"r"*
@
and
the
tilt
screw
@
to
the
same
angte
to
shift the
recording/playback
head
so it
is
parallel
to
the
jig
board for
height
readjustment.
After
the
adjustment
is
completed,
tighten
the lock
nuts.
4-3
Azimuth
Adjustment
Playback
test
tape
A-BEX
TCC-1
53 and
perform
the
adjust_
ment
by turning
the
azimuth
adjustment
screw
@
until
A
and
B in
the
Lissajous
wave
figure
are
at
the
maxrmum
and the
minimum positions
respectively.
After
azimuth
ad_
justment
is
completed,
check
again
to make
sure
there
is no
dislocation
on the head
height
with
the readjusting jig
THG-801.
After
the
adjustment
is
completed,
secure
the
lock
nuts
on the
adjusted
parts.
Jig
boord
Ji9
stick
Jig
shoft
5. Erasure
Head
@
Exchange
5-1 Remove
the
locking
scre*
6i)
for
the
erasure
head.
5-2 Remove
the
solder
on the
head
wire,
and
separate
the
me_
chanical
unit
to
dismount
the
erasure
head.
6. Tape
guide
height
verification
Set the
jig
board
THG-801
on the
mechanical
unit.
Adjust
it
by
turning
the
height
adjustment
screw
@
,o that
the
3.g mm
part
on
the
jig
stick
THG-8O1
jig
shaft
move
without
contacting
the
tape guide
part
of
the
tape
guide.
7.
Verifying
fast-forwardingtorque
Load
a cassette-type
torque
meter
and
verify
that
the
reading
on
the
torque
meter
at the
median
value
is
30_70 g_cm
during
playback.
lf
the reading
is
outside
the
standard,
verify
the
voltage
of the
reel
motor
(4.1
V
+0.3
V).
lf the
voltage
is low
the
torque
is
weak
and when
the
voltage
is
high
the
torque
is
strong.
Also
verify
the
reel
thrusting
gutter
in ltem
g.
8. Verification
Reel
Driver
Thrust
Movement
Verify
that
the
thrust
movement
is
3.0 to 4.0
mm.
9. FF
and
REW
Torque
Verification
O When
using
cassette-type
torque
meter:
Verify
that
the readings
at the
end
of the fast_forward
and
rewind
is
90-
18O
g-cm.
O
Load
the
cassette
half-modified
jig
and hook
the
tip
of a
dial
tension
meter
(full
scale
100_3OO
g)
on the
triangle
part.
Switch
to
the
FF
(REW)
position
and feed
a tape
at
a some_
what
slower
pace
than
the
speed
of
the
tape
that
is rolled
in.
Verify
that
the
value
on the
dial
tension
meter
at that
time
is
more
than
90
g-cm.
1O.
Back
tension
torque
verification
for
recording/playback
Load
a cassette-type
torque
meter
to
verify
that
the reading
on
the
torque
meter
for
recording/playback
is
6
to
12 g_cm
and
there
is no
unevenness.
lf
the
reading
is
outside
the
standard
values,
verify
the reel
thrust
gutter
or
replace
the
REEL
BASE
BLK
@
.
1 1.
FF
and
REW
Time
Verification
Load
a DENON
HD-7E/60
cassette
tape
and
verify
that
the
FF
and REW
time is
80 to
1 1O
seconds.
lf
the reading
is
outside
the
standard
values,
verify
ltems
8 and 10.
12.
Accidental
erasure
prevention,
metal
and
chrome
switch
function
verification
Verify
that
switch
(3)
is
functioning
normally
depending
on
whether
the
hole
is
present
or not.
Tit
t
\
gte
A-BEX
TCC-153
Screw
[ock
Screw
tock
15