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DtOffM AUDIO
Adjustment
of
the focus off-set
Coarse adjustment
A. -
Place potentiometer 3517 approximately in
mid-position.
- Put test disc 5 on the turntable.
- Bring the player in service position
1.
- The focusing motor can now start focusing 16x and
when it has found the focal point a
"1"
will appear
on the display.
- If this does not happen, turn potentiometer 3517
clockwise or anti-clockwise a little.
- Here after the fine adjustment of the focus off-set
has to be carried out.
B. - Place with potentiometer 3517 the focusing motor
in optical horizontal position.
- Here after the fine adjustment of the focus off-set
has to be carried out.
Fine adjustment
- Bring the player in service position
2.
- Adjust potentiometer 3517 for a voltage across 2545
(test point 27) of 400 mV
±
40 mv.
Note: Notice that the CDM is in a horizontal position.
Changing the transformer connections
6
5
UNITS SOLD IN
U.S.A.
CANNOT BE CHANGED
A
DEDICATED
TRANSFORMER
6
5
22DV~
240V~
Fig. 6
AS THEY HAVE
2
42 492 A12
If the set should be connected to a mains voltage that
deviates from the voltage mentioned on the type plate,
the transformer connections should be changed, as
indicated in Fig. 6.
DETAILED MEASURING METHOD
I. µP IC6551
•
Servicing program
For initiation of the servicing program see: General
checkpoint: Initiation of the service program.
•
Reset (pin 17)
When the supply voltage is switched on, a positive
pulse should be present.
•
X•tal out (pin 16; test point 31)
The frequency of this signal should be 6 MHz.
• 1
2
c
(pin
3;
test point
29)
• 1
2
0
(pin
2;
test point
31)
These should be activity at test point 29 and 31 in
position play.
•
MSTP (pin 20; test point 78)
4-3
When, after RD "high", the MSTP is "high" for a short
moment(>
0.2
sec.), the turntable motor control will
be switched on.
The turntable motor is controlled by the MC-signal
(test point 12).
To check MC, see: "Decoder A IC". To check the
turntable motor control see CDM2 Service Manual
"Checking of the motor control".
•
BO (pin 11; test point 36)
81
(pin
1 O;
test point
34)
B2 (pin
9 ;
test point 33)
B3 (pin 8 ; test point 32)
With the BO
+
83 signals
• The radial control is switched on.
• The level on the
DAC
output is controlled.
-
In the SEARCH mode, there should be activity on all
4
test points.
In the following positions the signals BO + 83 are
stable:
STOP
PLAY
Service
Service
signal
pas. 0,1,2
pos.3
BO
"low"
"high"
"low"
"high"
81
"high"
"high"
"high"
"high"
82
"high"
"high"
"high"
"high"
83
"low"
"low"
"low"
"low"
• TL
(pin 12; test point 16)
- The TL signal (Track Lost) Is used to tell the µP that
track loss threatens. The µP then can give correction
signals with BO + 83.
-
In the "SEARCH" mode, or when the player is bumped
against, there are pulses on test point 16.
•
REdig (pin
13;
test
point
37)
The REdig signal (= Radial Error Digital
=
radial
deviation) is used to determine the place of the arm
relative to the track and to check/corect in case of
track jumping or bumping against the player.
In servicing position 3 or in the PLAY mode, a square
wave should be present on test point 37.
Because of frequency variations, this square wave is
hard to trigger.
•
DODS (pin 22; test point 19)
The DODS signal (= Drop Out Detector Suppression)
avoids that Drop-Out signals influence the arm control
durinq track jumping.
Position
POWER Servicing
PLAY
SEARCH
of
ON
pos.3
player
DODS
u'U
signal
11
low"
"high"
"high"
MDA00364
cs
9 985
T12
-
638
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