Philips CD911 - Page 16

16
WARNING !!! LASER DAMAGE !!!
For
measurements
on
the
laser
(flexconnector
pin
1052-6),
certain
conditions
are
absolutely
necessary
for
precaution
of
laser
damage.
The instruction and sequence for measuring laser current is as follows:
-turn off mains power.
-wait for > 1 second
-connect
a
multimeter
(high
input
impedance,
not
grounded
accross
resistor
3022.
(*)
-turn on mains power and go to play mode.
-reading of measurement value (current = reading/4R7) (**)
-go to stop and turn off mains power.
-disconnect the multimeter.
In
case
of
a
laser
volrage
measurement,
connect
the
multimeter
accross
elcap
2025,
using
the
same
procedure
as
mentioned
above.
** |f current is > 95 mA, you can be sure that the laser is defect;
If
the
current
is
increasing
during
reading
(within
+/-
10
seconds),
you
can
be
sure
that
the
laser
is
severely
damaged.
* 1)-Laser supply o.k.?
Voltage accross C2025: 4...5V
** 2)-Laser current 0.k.?
Voitage accross R3022: 150...450mV
3)-Lens clean?
Visual control. Check for dust,grease.
Take attention for the blue coating.
4)-Check inputs.
Switch back to service mode 0.
Connect a 2.4 MOhm resistor from
1052 - 9 to 5V: Voltage on pin 5 of IC7000 < 50mV.
1052 - 10 to 5V: Voltage on pin 6 of IC7000 < 50mv.
1052 - 12 to 5V: Voltage on pin 7 of IC7000 < 50mV.
1052 - 11 to 5V: Voltage on pin 10 of IC7000 < 50mvV.
1052 - 8 to 5V: Voltage on pin 11 of IC7000 < 50mV.
5)-Diodes o.k.?
Use IR LED of remote control.
A
half
sine
wave
must
be
measured
on
the
diodes
(on
pin
8,9,10,11,12
of
conn.
1052)
in the 10mV range.
*
6)-V guard o.k.?
Voltage accross C2025: 4...5V
7)-Check connections between main PCB and CDM
8)-Flex 0.k.?
Measure diode functions on CDM-flex
9)-Check components around IC7061
R3022,R3021,R3020
C2025,C2060,C2064
10)-LD ON voitage o.k.?
Measure on pin 2 of IC7000:4...5V.
PCS 60 679
Lightpath
Laser supply
0.k. ?
Laser currrent
Check input
IC7000
Diodes test
o.k. ?
16
N
N N
23 7
Replace Repair
CDM
N N
LD on voltage
o.k.?
24
Clean Y N
18
Replace
N IC7061 +
Repair
26 12
Replace Replace
1C7000 opamp 7061
N Y
N
LD on voltage
0.k.?
Y
14 15
Replace
Job done 17000
Check
connections
Y
20 22 25
Replace Replace Repair
I¢7000 CDM