81
DEH-P945R,DEX-P99R
• 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
6.3 CHECKING THE GRATING AFTER CHANGING THE PICKUP UNIT
Oscilloscope
CONTROL UNIT
Summary of Contents for DEH-P945R
Page 13: ...13 DEH P945R DEX P99R ...
Page 14: ...14 DEH P945R DEX P99R 2 4 CD MECHANISM MODULE ...
Page 23: ...23 DEH P945R DEX P99R 5 6 7 8 5 6 7 8 D C B A D D b A A ...
Page 24: ...24 DEH P945R DEX P99R 1 2 3 4 2 3 4 D C B A 1 D a D a D b E D ...
Page 25: ...25 DEH P945R DEX P99R 5 6 7 8 5 6 7 D C B A 8 D a D a D b I J N O I J ...
Page 26: ...26 DEH P945R DEX P99R 1 2 3 4 2 3 4 D C B A 1 D a D b D b A ...
Page 27: ...27 DEH P945R DEX P99R 5 6 7 8 5 6 7 D C B A 8 D a D b D b A ...
Page 31: ...31 DEH P945R DEX P99R ...
Page 32: ...32 DEH P945R DEX P99R 1 2 3 4 1 2 3 4 D C B A B A B 3 3 FM AM TUNER UNIT ...
Page 33: ...33 DEH P945R DEX P99R 5 6 7 8 5 6 7 8 D C B A B ...
Page 39: ...39 DEH P945R DEX P99R 5 6 7 8 5 6 7 8 D C B A F a F a F b ...
Page 41: ...41 DEH P945R DEX P99R 5 6 7 8 5 6 7 8 D C B A F b F a F b GGC1325 AM30 10 45dBs ...
Page 42: ...42 DEH P945R DEX P99R 1 2 3 4 1 2 3 4 D C B A 3 6 ASL UNIT L L A ...
Page 48: ...48 DEH P945R DEX P99R 1 2 3 4 2 3 4 D C B A 1 A TUNER AMP UNIT A ...
Page 49: ...49 DEH P945R DEX P99R 5 6 7 8 5 6 7 D C B A 8 A SIDE B ...
Page 51: ...51 DEH P945R DEX P99R D C B A 1 2 3 4 1 2 3 4 B FM AM TUNER UNIT B SIDE B ...
Page 52: ...52 DEH P945R DEX P99R 1 2 3 4 1 2 3 4 D C B A 4 3 CD MECHANISM MODULE SIDE A D CONTROL UNIT D ...
Page 55: ...55 DEH P945R DEX P99R 1 2 3 4 1 2 3 4 D C B A J PHOTO FPC UNIT I J 1 2 3 P1 P3 P2 ...
Page 57: ...57 DEH P945R DEX P99R 5 6 7 8 5 6 7 8 D C B A C SIDE A SIDE B ...
Page 58: ...58 DEH P945R DEX P99R 1 2 3 4 1 2 3 4 D C B A 4 5 DSP UNIT SIDE A DSP UNIT F F ...
Page 59: ...59 DEH P945R DEX P99R D C B A 1 2 3 4 1 2 3 4 SIDE B F DSP UNIT F A CN222 ...
Page 98: ...98 DEH P945R DEX P99R TC7S08FU 1 IN B 2 IN A 3 GND 4 OUT Y 5 VCC AK4321VF ...
Page 100: ...COMMON SEGMENT 7 1 2 DISPLAY CAW1471 DEH P945R EW CAW1493 DEX P99R EW 100 DEH P945R DEX P99R ...
Page 107: ...107 DEH P945R DEX P99R ...
