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Symptom 1: the player shell is displayed, but video from
the disc cannot be displayed. If this condition exists, the
Video Encoder Panel and video analog circuits are func-
tioning. Since the player shell is displayed, the video syn-
thesizer circuit is functioning. However, there must be
a fault on the MMC Panel, since this is where the video
decoding takes place. Thus the problem is isolated to the
video decoding section on the MMC Panel.
Symptom 2: no video. This symptom may be caused
by either the Video Encoder Panel or by the MMC Panel.
A few voltage and signal measurements can quickly
isolate the problem. Hint, also check all the video outputs:
S-video, RF, and CVBS. If video is not present from any
output, check the RGB, composite sync, and power source
inputs from the CD Unit to the Video Encoder Panel
(Connector 1061 on the bottom of the Video Encoder
Panel).
If these signals are present, the
MMC
Panel's decoder
circuits are functional. Further checks of the Video Encoder
circuit can isolate the problem further. Check the Video
Encoder IC. Also check Vcc1 and Vcc2 to the Video
Encoder IC. If both sources are missing, check Resistor
3660. If Vcc1 is missing, check Resistor 3618 and if Vcc2
is missing, check 3619.
Symptom 3: no color. This symptom is most likely caused
by a problem in the ENCODER circuit. Check the subcarrier
oscillator at Pin 6 of the Video Encoder IC. If this signal is
present (correct frequency), check the chroma output sig-
nal at Pin 15. If there is no chroma output, IC7601 may be
the fault. Also check for short circuits between pins of the
IC. If the chroma is present, check the chroma input at Pin
17. If the chroma is not present here, check the coupling
components between Pins 15 and 17. If there is chroma at
this point, check the composite output at Pin 20. If the
chroma is missing, suspect the Video Encoder IC (IC7601 ).
7.2.1 Measurements & adustments power supply
1006
CAUTION.
Never turn on the power supply if no load resistor has
been connected.
-· For service purposes you only have to connect a load
resistance to the
+
5,2V supply voltage.
Use a 4 Ohm / 25W resistor.
Of course in that case the other supply voltages are not
in accordance with the specification.
Safety regulations require that the set under repair
should be restored to its original state and that compo-
nents identical to the ones specified should be used.
For reasons of safety, components marked should be
replaced by identical components. For code numbers
refer to the parts list of electrical components.
Beware of the live parts!
7.2.1.1 Checkpoints
Check the following supply voltages:
NOMINAL
SUPPLY
VALUE (DC)
CONNECTOR/PINS
+
5,2V
+
5,3V DC
P0006 pin 4
+
12 V
+
12,1V DC
P0005 pin 1
or M7 pin 8 (MMC Panel)
- 12 V
- 12,1V DC
P0005 pin 2
or M7 pin 7 (MMC Panel)
-sv
- 8V DC
P0004 pin 6
or C1 pin 3 (CD Panel)
+sv
+
8V DC
P0004 pin 7
or C1 pin 2 (CD panel)
+
30 V
+
28,5V DC
P0004 pin 8
or C1 pin 1 (CD panel)
All voltages have been measured relative to earth.
PCS 61877
7.2.1.2 Adjustments
Adjustment+ 5,2V supply voltage
Adjust R3020 for a voltage of 5.3V DC ± 40 mV on test
point 51.
For practical reasons it is also possible to measure at pin 3
of connector G12 on the extension board.
7.2.2 Measurements & adjustments CD panel
1004
In the circuit diagrams and on the drawings of the panels
measuring points are marked with: .
Some times signals to be measured are pointed as for
example: IC7181 pinl
All DC signals are measured with an universal electronic
voltmeter.
All AC signals are measured with an oscilloscoop
7.2.2.1 Lasercurrent.
The lasercurrent is adjusted in the CDM9 and is a factory
adjustment. After replacing a defective CDM the laser
current does not need to be adjusted.
Play track 1 of testdisc 5, the voltage accross item
3114(measuring point 1 and point 2) on the CD panel
should be: 0,7 V /DC± 10 %.
7.2.2.2 Focus signal.
Play track 1 of testdisc 5, the voltage accross item 2151
(measuring point 3 and GND) on the CD panel should be:
+ 400 mV / DC
±
10%.
7.2.2.3 Starting signal.
Insert a disc and measure accross item 2112 (measuring
point 4 and GND).
After pushing the play button the next picture appears on
the oscilloscoop:
The signal is triggered by the Si/RD signal on IC7101 pin 6.
7.2.2.4 Motorcontrol signals.
Insert testdisc 5.
Measure accross IC7181 pin1 and GND, after pushing the
play button the next picture should appear on the oscillos-
cope.
After a while, when playing track 1, the voltage should be:
- 1.7 V DC± 10%
Play track 1 of testdisc 5, the voltage across measuring
point 6 and ground should be: 3.2 Volt DC ± 10%
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