76
FH-P8800
•
Note :
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 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, REFO
• 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
adjustment the display should now read "81". Press key
3
2 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
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 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
average angle.
•
Hint
Reloading the disc changes the clamp position and may decrease the "wobble".
F
REFO
E
100k
Ω
390pF
100k
Ω
390pF
E
REFO
F
REFO
L.P.F.
L.P.F.
CONTROL UNIT
Xch
Ych
Oscilloscope
6.3 CHECKING THE GRATING AFTER CHANGING THE PICKUP UNIT
Содержание FH-P8800
Страница 5: ...FH P8800 5 2 2 EXTERIOR ...
Страница 6: ...6 FH P8800 ...
Страница 10: ...10 FH P8800 2 3 CD MECHANISM MODULE ...
Страница 12: ...12 FH P8800 2 4 CASSETTE MECHANISM MODULE ...
Страница 23: ...23 FH P8800 5 6 7 8 A B C D 5 6 7 8 B KV1410 23 ...
Страница 24: ...24 FH P8800 C CD POWER UNIT A 1 2 3 4 B C D 1 2 3 4 C 3 3 CD POWER UNIT ...
Страница 25: ...25 FH P8800 A H I CD MECHA MODULE 5 6 7 8 A B C D 5 6 7 8 C ...
Страница 28: ...28 FH P8800 CN751 A CONNECTOR PIN A 1 2 3 4 B C D 1 2 3 4 3 5 DSP UNIT G ...
Страница 29: ...29 FH P8800 G DSP UNIT 5 6 7 8 A B C D 5 6 7 8 G ...
Страница 31: ...31 FH P8800 5 6 7 8 A B C D 5 6 7 8 P SERVO DSP DAC SINGLE CD CONTROLLER DAC 8 380MHz CN701 C CN1241 H ...
Страница 35: ...35 FH P8800 ...
Страница 36: ...36 FH P8800 A 1 2 3 4 B C D 1 2 3 4 3 7 CASSETTE MECHANISM MODULE J CN201 A HD1 HEAD ASSY EXA1452 DECK UNIT J ...
Страница 39: ...39 FH P8800 B C CN1251 CN251 J NA REAR UC MODEL FRONT SUBWOOFER REAR 5 6 7 8 A B C D 5 6 7 8 A SIDE A ...
Страница 40: ...40 FH P8800 FOPEN FCLOSE A 1 2 3 4 B C D 1 2 3 4 A A AUDIO AMP UNIT ...
Страница 41: ...41 FH P8800 5 6 7 8 A B C D 5 6 7 8 A SIDE B ...
Страница 42: ...42 FH P8800 A 1 2 3 4 B C D 1 2 3 4 4 2 FM AM TUNER UNIT B A SIDE A B FM AM TNER UNIT ...
Страница 43: ...43 FH P8800 1 2 3 4 A B C D 1 2 3 4 B FM AM TNER UNIT B SIDE B ...
Страница 44: ...44 FH P8800 A 1 2 3 4 B C D 1 2 3 4 4 3 CD POWER UNIT C CD POWER UNIT C ...
Страница 45: ...45 FH P8800 A CN701 IP BUS H CN701 5 6 7 8 A B C D 5 6 7 8 C SIDE A ...
Страница 46: ...46 FH P8800 A 1 2 3 4 B C D 1 2 3 4 C CD POWER UNIT C ...
Страница 47: ...47 FH P8800 5 6 7 8 A B C D 5 6 7 8 C SIDE B ...
Страница 48: ...48 FH P8800 A 1 2 3 4 B C D 1 2 3 4 4 4 GRILLE PCB A D D 4 5 6 CN904 E GRILLE PCB A D GRILLE PCB A ...
Страница 49: ...49 FH P8800 5 6 7 8 A B C D 5 6 7 8 D 1 2 3 CN906 F CN801 CASNS A SIDE A SIDE B ...
Страница 51: ...51 FH P8800 5 6 7 8 A B C D 5 6 7 8 E SIDE A SIDE B ...
Страница 53: ...53 FH P8800 5 6 7 8 A B C D 5 6 7 8 DSP FUNC AUDIO RESET BAND TAPEEJ SCROLL OURCE F SIDE A SIDE B ...
Страница 54: ...54 FH P8800 A 1 2 3 4 B C D 1 2 3 4 4 7 DSP UNIT G DSP UNIT G SIDE A ...
Страница 55: ...55 FH P8800 A CN751 1 2 3 4 A B C D 1 2 3 4 G DSP UNIT G SIDE B ...
Страница 57: ...57 FH P8800 1 2 3 4 A B C D 1 2 3 4 1 100 76 26 50 25 75 51 CONTROL UNIT H H SIDE B ...
Страница 59: ...59 FH P8800 1 2 3 4 A B C D 1 2 3 4 L K REEL PCB L ...
Страница 77: ...77 FH P8800 Grating waveform Ech Xch 20mV div AC Fch Ych 20mV div AC 45 0 75 60 30 90 ...