96
DEX-P1R,DEH-P946,DEX-P1
• Note :
Unlike previous CD mechanism modules the grating angle of the PU unit cannot be adjusted after the PU unit is
changed. The PU unit in the CD mechanism module is adjusted on the production line to match the CD mecha-
nism module and is thus the best adjusted PU unit for the CD mechanism module. Changing the PU unit is thus
best considered as a last resort. However, if the PU 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 TR+ and TR- buttons, move the PU unit to the innermost track.
3. Press key 3 to close focus, the display should read "91". Press key 2 to implement the tracking balance adjust-
ment the display should now read "81". Press key 3 4 times. The display will change, returning to "81" on the
fourth press.
4. As shown in the diagram above, monitor the LPF outputs using the oscilloscope and check that the phase differ-
ence 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 PU 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 aver-
age angle.
• Hint
Reloading the disc changes the clamp position and may decrease the "wobble".
100k
Ω
390pF
100k
Ω
390pF
E
REFO
F
REFO
Xch
Ych
L.P.F.
L.P.F.
E
F
REFO
6.4 CHECKING THE GRATING AFTER CHANGING THE PICKUP UNIT
Oscilloscope
CONTROL UNIT
Summary of Contents for DEH-P946
Page 16: ...16 DEX P1R DEH P946 DEX P1 2 4 CD MECHANISM MODULE ...
Page 21: ...21 DEX P1R DEH P946 DEX P1 5 6 7 8 5 6 7 8 D C B A A a A b A a C B K FLAP SENSE PCB 4R7 K ...
Page 23: ...23 DEX P1R DEH P946 DEX P1 5 6 7 8 5 6 7 8 D C B A FU801 ICP N10 4A A a A b A b ...
Page 27: ...B C K FLAP SENSE PCB 27 DEX P1R DEH P946 DEX P1 5 6 7 8 5 6 7 8 D C B A A a A b A a K ...
Page 31: ...31 DEX P1R DEH P946 DEX P1 5 6 7 8 5 6 7 8 D C B A D b A A D ...
Page 32: ...32 DEX P1R DEH P946 DEX P1 1 2 3 4 1 2 3 4 D C B A D a D a D b E D ...
Page 33: ...33 DEX P1R DEH P946 DEX P1 5 6 7 8 5 6 7 8 D C B A D a D a D b N O I J I J ...
Page 34: ...34 DEX P1R DEH P946 DEX P1 1 2 3 4 1 2 3 4 D C B A D b D a D b A ...
Page 35: ...35 DEX P1R DEH P946 DEX P1 5 6 7 8 5 6 7 D C B A 8 D a D b D b A ...
Page 39: ...39 DEX P1R DEH P946 DEX P1 ...
Page 40: ...40 DEX P1R DEH P946 DEX P1 1 2 3 4 1 2 3 4 D C B A A B 3 3 FM AM TUNER UNIT DEX P1R UC B ...
Page 41: ...41 DEX P1R DEH P946 DEX P1 5 6 7 8 5 6 7 8 D C B A B ...
Page 43: ...43 DEX P1R DEH P946 DEX P1 5 6 7 8 5 6 7 8 D C B A B ...
Page 44: ...A CN801 44 DEX P1R DEH P946 DEX P1 1 2 3 4 1 2 3 4 D C B A 3 5 KEYBOARD PCB C ...
Page 49: ...49 DEX P1R DEH P946 DEX P1 5 6 7 8 5 6 7 8 D C B A F a F a F b ...
Page 51: ...51 DEX P1R DEH P946 DEX P1 5 6 7 8 5 6 7 8 D C B A F b F a F b ...
Page 52: ...52 DEX P1R DEH P946 DEX P1 1 2 3 4 1 2 3 4 D C B A 3 7 ASL UNIT L L A ...
Page 58: ...58 DEX P1R DEH P946 DEX P1 1 2 3 4 1 2 3 4 D C B A A TUNER AMP UNIT A ...
Page 59: ...59 DEX P1R DEH P946 DEX P1 5 6 7 8 5 6 7 8 D C B A A SIDE B ...
Page 61: ...61 DEX P1R DEH P946 DEX P1 D C B A 1 2 3 4 1 2 3 4 B FM AM TUNER UNIT B SIDE B ...
Page 65: ...65 DEX P1R DEH P946 DEX P1 1 2 3 4 1 2 3 4 D C B A 1 2 3 P1 P3 P2 J PHOTO FPC UNIT I J ...
Page 67: ...67 DEX P1R DEH P946 DEX P1 5 6 7 8 5 6 7 8 D C B A C SIDE A SIDE B ...
Page 68: ...68 DEX P1R DEH P946 DEX P1 1 2 3 4 1 2 3 4 D C B A 4 5 DSP UNIT SIDE A DSP UNIT F F ...
Page 69: ...69 DEX P1R DEH P946 DEX P1 D C B A 1 2 3 4 1 2 3 4 SIDE B F DSP UNIT F A CN222 ...
Page 117: ...117 DEX P1R DEH P946 DEX P1 COMMON SEGMENT 7 1 2 DISPLAY CAW1470 DEX P1R UC ...
Page 118: ...DEX P1R DEH P946 DEX P1 118 CAW1471 DEH P946 ES DEX P1 ES COMMON SEGMENT ...