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3-1
TROUBLE SHOOTING
(FAULT FINDING TREE)
START-UP PROCEDURE
Follow the path
of
the
faultfinding
tree
beginning
at
the
top
left.
Perform
the actions
you
come
across
in
the
various blocks.
Look
at
the various side
branches
to find
out
if
the
information
you see
there applies
to
your problem.
If,
for
instance,
you
find
the
indication
^'cJtspfaVl
_
this
means
that
no
picture
appears on
the
display.
If
you
establish
this
fault,
follow the
branch and perform
the
recommended
actions.
Check
the signals
mentioned.
In
a
number
of
branches
further
reference
is
made
to
measurements
you
could carry
out.
These measurements
are explained
in
several tables
further
on
in
this
manual.
KBSe
0-3
KBSC
0-2
DDASC3
6512
HFI
TURNTABLE
MOTOR
X-TAL
TL
MC
DODS
T™
ORA
WSAB
6535
6536
DEEM
6541
ATSB
QCL
CLAB
6542
6544
6561
6542
6554
QDA
EFAB
6543
6545
6563
6543
6555
SWAB/SSM
DAAB
6564
6544
6558
SCAB
CLBD
6565
6545
SDAB
DABD
6535
WSBD
6536
MUSB
|
AM
1
KILL
1
SEE
SPECIFICATION
1
MEASUREMENT
B-3
CHECK OF THE PHOTODIODES
Step
Signal
Mode
o
0
C=D
o
o
El
• • •
•
#
Remarks
1
D2
power on
-
signal
4E6E7E8
Signal
depends on
Distance
lens
+
IR
LED
of
remote
control
D1
D3
D4
<t>
—
0—i
T-22407A
B-4
CHECK OF LASER
SUPPLY
The
laser,
the lasersupply plus the
monitor diode form a
feedback
system.
A
defect
in
the lasersupply
may
result
in
the destruction
of
the
laser.
If,
in
that
case, the
laser
is
replaced,
(=
complete
D.C.M.-unit) the
new
laser
will
also
become
defective.
However,
it
is
impossible
to
check and
repair
a
feedback system
if
a
link
is
missing.
For
this
reason
the
laser
supply
can be checked
with teh
replacement
circuit
for
laser
assembly.
Step
Signal
Mode
o
C=D
o
o
Remarks
1
LO
serv.
pos.
2
SK
<
§>
®
i
1.8CV
<2.3
PRS05539
LM
<
0
>
®
i
170<mV
<220
2
LO
serv.
pos.
2
SK
1
.8<V <2.3
PRS05540
LM
®
—
i
170<mV
<220
3
LO
Power
on
0V
±
0.2V
No
light
T-22407B
B-4
LASER
CURRENT ADJUSTMENT
Step
Signal
Mode
O
0
C=I7
o
0
El
e
e
Remarks
1
-
Power
off
^
®
—
i
R3520
Ik
n
-
Pre-adjustment
Ohmic
value
2
Eye-pattern
HF
Power
on
Test
disc
5
play
^-0-i
-
-
EYE
pattern
3
laser
current
=
voltage
across
R3508
Test
disc
5
play
track
1
R3520
50
mV
DC
-
High-ohmic
measurement
T-22407C
B-5
ADJUSTMENT OF FOCUS-OFFSET
Step
Signal
Mode
O
0
o
0
E|
e
e
Remarks
1
-
Power on
no
disc
-
R3568
-
-
adjust
for optical
mid-position
of
the
focus motor
2
FE
LAG
Play
Test
disc
5
Track
1
27
R3568
400mV ±
40
mV
DC
-
fine
adjustment
T-22407D
CS
22
789
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