Denon DCD-1500 - Servo System Checks and Operations

)
2. NOTES ON OPERATION BUETONS IND 3. CHECKING OF FOCUS, SPINDLE,
SERVICE MODE : TRACKING, AND SLIDE SERVO ,
as * OPERATIONS
{1) Play Button (> PLAY) — ; © Be sure to observe the preceding “Turntable Height
Each
push
of
the
button
to
actuate
the
following
Adjustment”
at
the
time
removed
the
turntable
or
in
servo circuit operation in consecutive order. Pushing case of disc hit the tray.
it four times actuates-all servo operations. Also when repiaced the parts, be sure to do the follow-
@
Push
it
once
:
Actuate
focus
servo
circuit
ing
servo
system
adjustments
prior
to:
these
adjustments.
("1° appears on the calendar.)
@ Push it twice : Actuate spindle servo circuit {1) Turn off the power and. disconnect the jumper to
(“2" appears on the calendar.) pins @ and @ of TP-204. Then turn on the
© Push it three times : Actuate tracking servo circuit power and operate disc halder open-close button
(3° appears on the calendar.) { & OPEN/CLOSE} to load the standard disc.
@ Push it four times : Actuate slide servo circuit Note: When TP-204 is shorted, disc hoider can not
(4
appears
on
the
calendar.)
be
opened
or
closed
even
though
the
disc
holder open/close button is pressed. Displace
the lock arm from the lock point, enables
Joading of disc by drawing the disc hotder
frontward manuaily. In this case, turning on
and off the power is not essential. + (
When focus servo operation is defective, it will not go
to the next step however the button is pressed.
(2) Stop Button ( s STOP}
Pushing the button to cancel all circuit operations.
To check servo circuit again or recheck from the
beginning,
put
it.
(2)
Short-circuit
pins
@
and
@®
of
TP-204
and
turn
on the power. Check to see that” {7/7 ” blinks on
(3) Track Button (Kt PT) the indication window.
in service mode, this button has two functions.
‘D tn stop state (inciude the condition after the power {3}
is turned on):
The pick-up slides.
While pushing " ” side, pick-up moves to disc
center; whie pushing ‘' & ‘ side, it moves to disc
outer circle.
tn the state when play button { » PLAY) is pressed
four times and all servo circuits are activated:
Performs track jump.
There are three types of track jump (1, 10, 100
tracks} and are switchable by pause button (24
PAUSE}.
* Except for the above two conditions, this button
will not function even if it is pressed.
{An example: In such a case when the play buttort~
is pressed three times and the servos are activated
up to tracking. )
Checking of Focus Servo Operation.
Pushing the play button ( » PLAY) starts focus
search. When the disc is loaded, by detecting of a
focusing point of the laser beam on the disc surface
to activate focus servo.
When .the disc is not loaded, repeats focus search
three times and the returns to the former state (the
condition before pushing the button).
When the button is continuously pushed, repeats !
focus search with or without loading of the disc. ,
When the button is released, starts detecting a focus-
ing point within the three times of search operation.
In case of focus servo is properly worked, the
position of object lens of laser pick-up becomes (
approximately the same height as actuator cover.
Confirmation of the proper focus servo operation
can be checked by a “squeak” sound reproduced
when turning the disc clockwise or counterclockwise
with the hand lightly.
This sound derives from the movement of actuator
for focus servo, so checking of this sound namely to 7
confirm proper operation of focus servo. F
Note: Confirming up and down movements of
be object lens enables checking of focus
i as : search operation. Remove the disc ..and
hen activate all:servo circuits, r . detach the disc clamper so as to look object
lens movement more easily, then push play
button ( » PLAY)... The object lens repeats
moving three times up and down then stops.
Through this movement the operation of
actuator. for focus control can be checked, -
cS)
e Pushing the track button {>}. while all servo
circuits are activated makes the tracking servo gain
lowered.
Note that the adjustment of tracking servo explain-
ed later must be ‘performed under the tracking
servo is in high gain. To put it in high gain condi-
tion, turn off the power once and turn on again,
(4). Pause Button ( [] PAUSE)
Switches track jump mode.
tt is always reverted to 1. track jump node whenever
the power is turned on. ee
Each push of the button shifts the mode to 10-track. :
* 100-track, .1- track ston Ttrack-jump “fit
2 10-track jump {7 f°; 100-track. jump
links on the display to show respective mode
nfirmation of track j jump ‘mode can be obt: