68
DEH-P3370XM
•
Note :
The grating angle of the PU unit cannot be adjusted after the PU unit is changed. The PU unit in the CD mecha-
nism module is adjusted on the production line to match the CD mechanism 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 when the PU unit is changed.
•
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 taking a long time for track searching.
•
Method :
• Measuring Equipment
• Oscilloscope, Two L.P.F.
• Measuring Points
• E, F, VREF
• 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
]
and
[
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
. 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
VREF
F
VREF
Xch
Ych
L.P.F.
L.P.F.
VREF
E
F
6.2 CHECKING THE GRATING AFTER CHANGING THE PICKUP UNIT
CONTROL UNIT
Oscilloscope
Summary of Contents for DEH-P3370XM UC
Page 4: ...4 DEH P3370XM A C B 2 2 EXTERIOR ...
Page 6: ...6 DEH P3370XM D 2 3 CD MECHANISM MODULE ...
Page 28: ...F RF MODULE 28 DEH P3370XM 1 2 3 4 1 2 3 4 D C B A 3 6 RF UNIT GUIDE PAGE F F a ...
Page 29: ...29 DEH P3370XM 5 6 7 8 5 6 7 8 D C B A F b F E CN502 ...
Page 30: ...F RF MODULE 30 DEH P3370XM 1 2 3 4 1 2 3 4 D C B A F a F a F b 1 ...
Page 31: ...31 DEH P3370XM 5 6 7 8 5 6 7 8 D C B A F a F a F b 2 3 ...
Page 32: ...32 1 2 3 4 1 2 3 4 D C B A F a F b F b DEH P3370XM 1 ...
Page 33: ...33 DEH P3370XM 5 6 7 8 5 6 7 8 D C B A F b F a F b 2 3 E CN502 ...
Page 35: ...35 DEH P3370XM 5 6 7 8 5 6 7 8 D C B A G b G SSDEC DAC CAP ST19AF08BR20QMAA ...
Page 36: ...36 DEH P3370XM 1 2 3 4 1 2 3 4 D C B A S G DSP MODULE G a G a G b 1 ...
Page 37: ...37 DEH P3370XM 5 6 7 8 5 6 7 8 D C B A G a G a G b 2 CDEC E CN503 ...
Page 38: ...38 DEH P3370XM 1 2 3 4 1 2 3 4 D C B A G a G b G b DAC SDRAM CAP 1 ...
Page 39: ...39 DEH P3370XM 5 6 7 8 5 6 7 8 D C B A G b G a G b 2 SSDEC ST19AF08BR20QMAA ...
Page 42: ...42 DEH P3370XM 1 2 3 4 1 2 3 4 D C B A A TUNER AMP UNIT A ...
Page 43: ...43 DEH P3370XM 5 6 7 8 5 6 7 8 D C B A A SIDE B ...
Page 47: ...47 DEH P3370XM 1 2 3 4 D C B A 1 2 3 4 SIDE B D CLAMP 8EJ CONTROL UNIT D ...
Page 48: ...48 DEH P3370XM 1 2 3 4 1 2 3 4 D C B A 4 5 MAIN UNIT E IC Q F CN3 E MAIN UNIT RESET IP BU ...
Page 49: ...49 DEH P3370XM 5 6 7 8 5 6 7 8 D C B A SIDE A E IP BUS IP BUS CORD ASSY G CN201 A CN701 ...
Page 50: ...50 DEH P3370XM 1 2 3 4 1 2 3 4 D C B A E E MAIN UNIT ...
Page 51: ...51 DEH P3370XM 5 6 7 8 5 6 7 8 D C B A SIDE B E ...
Page 52: ...52 DEH P3370XM 1 2 3 4 1 2 3 4 D C B A 4 6 RF MODULE SIDE A F IC Q F RF MODULE XM ANTENNA ...
Page 53: ...53 DEH P3370XM 1 2 3 4 1 2 3 4 D C B A F SIDE B IC Q E CN502 F RF MODULE ...
Page 54: ...54 DEH P3370XM 1 2 3 4 1 2 3 4 D C B A 4 7 DSP MODULE SIDE A G IC Q G DSP MODULE ...
Page 55: ...55 DEH P3370XM 1 2 3 4 1 2 3 4 D C B A G SIDE B IC Q E CN503 G DSP MODULE ...
Page 69: ...69 DEH P3370XM Grating waveform Ech Xch 20mV div AC Fch Ych 20mV div AC 45 0 75 60 30 90 ...
