Dual 502 - Troubleshooting Common Issues; Platter and Speed Malfunctions; Tonearm and Stylus Problems; Acoustic Feedback

Fig.
12
7 E 3 '
wau
3mm
2.
Paul
Move tonearm (49) inwards.
The play be-
tween the stop pin (8)
and the shift
arm
(170) and the mounting
plate (124) should
be
0.2 to 0.5 mm. Adjust by
turning ec-
centric pulley (E), if necessary.
3. Power Switch
Extract power plug from
receptacle! Move
tonearm to its rest.
Power switch should
not switch off before the
tonearm (49) is
approx. 3 mm before its
rest (Fig. 12).
Adjust by bending the shift
arm (146).
Defect
Fig.
13
Pick
-up head
not parallel
to
platter.
Defect
Platter does
not run
after the
power plug
of the
unit has been
plugged into the p0 -
wer line receptacle
and the tonearm mo-
ved inwards.
Platter does not co-
me up to its requi-
red speed.
Stylus slips out
playing groove.
Tonearm
does not
wer on record or
wers onto record
quickly.
Cause
a)
b)
c)
a)
b)
c)
Belt (11)
not pro-
perly
put on.
Power
supply to
motor
(123) inter-
rupted.
Drive
pulley
(107)
slackened.
Drive
pulley
(107)
is
not
correct
for local
line
frequency.
Slippage
between
flat belt
and dri-
ve pulley
(107) or
flat belt
(11) and
platter (10).
Nominal
speed ma-
ladjusted.
of
Steel ball (161)
for
shut-off bar
missing.
lo- Damping
silicone oil
lo- in cue
control tube
too excessive
or too low.
Acoustic feedback. a)
Chassis components
(e.g. connecting
leads) rubbing on
board cut
out.
b) Connecting leads
too
tight.
Cause
The pick -up head
has been moved out of
Po-
sition on the tonearm tube
during transport.
Rmmedy
Remove platter. Using a screw driver slacken
screw on the pick -up head through the hole
provided for this purpose in the chassis
plate. After aligning the pick -up head re-
tighten screw.
Reime
a) Install
belt
properly put
on.
b)
Check
connection
on switch plate
(13Z,
and
power supply
plug.
c)
Retighten
drive pulley
(107).
a)
Replace
drive
pulley
(107).
b) Clean
friction
surfaces of
flat belt (11,
,
drive
pulley
(107) and
platter (10).
Re -
neu
flat
belt, if
necessary.
c)
Readjust
nominal speed.
Replace steel
ball (161).
Remove cue
control
assembly
(178)
(rarer to
page
7).
Unscrew
adjusting
bush
(179), remo-
ve lift
pin
(183). Remove
compression
spring.
Clean
lift
tube and
lift pin and
smear
even-
ly
with
"Wacker
Silicone
Oil AK
500
000".
Reassemble
parts. Wipe
off
excessive
silico-
ne oil
after
assembly.
a) Line
up
mounting board
cut-out
according
to
installation
instructions.
b)
Slacken or
lengthen
leads.
8