34
CDX-M2096ZRN
•
Note :
Unlike previous CD mechanism modules the grating angle of the pickup unit cannot be adjusted after the pickup
unit is changed. The pickup unit in the CD mechanism module is adjusted on the production line to match the CD
mechanism module and is thus the best adjusted pickup unit for the CD mechanism module. Changing the pickup
unit is thus best considered as a last resort. However, if the pickup unit must be changed, the grating should be
checked using the procedure below.
•
Purpose :
To check that the grating is within an acceptable range.
•
Symptoms of Mal-adjustment :
If the grating is off by a large amount symptoms such as being unable to close tracking, being unable to perform
track search operations, or track searching taking a long time, may appear.
•
Method :
•
Measuring Equipment
•
Oscilloscope, Two L.P.F.
•
Measuring Points
•
E, F, REFOUT
•
Disc
•
ABEX TCD-784
•
Mode
•
TEST MODE
•
Checking Procedure
1. In test mode, load the disc and switch the 5V regulator on.
2. Using the FWD and REV buttons, move the pickup unit to the innermost track.
3. Press key B to close focus, the display should read "11". Press key A to implement the tracking balance
adjustment the display should now read "5".
4. As shown in the diagram above, monitor the LPF outputs using the oscilloscope and check that the phase
difference is within 75° . Refer to the photographs supplied to determine the phase angle.
5. If the phase difference is determined to be greater than 75° try changing the pickup unit to see if there is any
improvement. If, after trying this a number of times, the grating angle does not become less than 75° then the
mechanism should be judged to be at fault.
•
Note
Because of eccentricity in the disc and a slight misalignment of the clamping center the grating waveform may be
seen to "wobble" ( the phase difference changes as the disc rotates). The angle specified above indicates the
average angle.
•
Hint
Reloading the disc changes the clamp position and may decrease the "wobble".
6.2 CHECKING THE GRATING
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Checking the Grating After Changing the Pickup Unit
REFO
E
F
REFO
REFO
E
F
L.P.F.
L.P.F.
CD CORE UNIT
Xch
Ych
Oscilloscope
100kW
100kW
390pF
390pF
Summary of Contents for CDX-M2096ZRN
Page 5: ...5 CDX M2096ZRN 2 2 EXTERIOR ...
Page 7: ...CDX M2096ZRN 2 3 CD MECHANISM MODULE 7 ...
Page 11: ...11 CDX M2096ZRN 3 BLOCK DIAGRAM AND SCHEMATIC DIAGRAM 3 1 BLOCK DIAGRAM A B C D E F G ...
Page 15: ...15 CDX M2096ZRN 5 6 7 8 A B C D 5 6 7 CSS1456 DIG A CN701 B b B 8 ...
Page 16: ...16 CDX M2096ZRN A 1 2 3 4 B C D 1 2 3 4 CCP1338 CCW1021 B B a B a B b ...
Page 17: ...17 CDX M2096ZRN 5 6 7 8 A B C D 5 6 7 8 S851 S852 CSN1033 C F D E B a B a B b C D E F ...
Page 18: ...18 CDX M2096ZRN A 1 2 3 4 B C D 1 2 3 4 CSS1456 DIG B a B b B b ...
Page 19: ...A CN701 19 CDX M2096ZRN 5 6 7 8 A B C D 5 6 7 B b B a B b 8 ...
Page 23: ...23 CDX M2096ZRN ...
Page 25: ...25 CDX M2096ZRN 1 2 3 4 A B C D 1 2 3 4 A EXTENSION PCB A SIDE B ...
Page 27: ...27 CDX M2096ZRN 1 2 3 4 A B C D 1 2 3 4 B SIDE B B CD CORE UNIT ...
Page 35: ...35 CDX M2096ZRN Grating waveform 45 0 75 60 30 90 Ech Xch 20mV div AC Fch Ych 20mV div AC ...
