Read Sony HCD-GNX660 / MHC-GNX660 Service Manual online
22
HCD-GNX660
RFAC Level Check
Connection:
Procedure:
1. Connect an oscilloscope to test point TP124 (RFAC) and TP
117(VC) on the BD84 board.
2. Turn the power on.
3. Put the disc (YEDS-18) in to playback the number five track.
4. Confirm that oscilloscope waveform is clear and check RFAC
3. Put the disc (YEDS-18) in to playback the number five track.
4. Confirm that oscilloscope waveform is clear and check RFAC
signal level is correct or not.
Note:
A clear RFAC signal waveform means that the shape “
◊” can be
clearly distinguished at the center of the waveform.
RFAC signal waveform
Checking Location: BD84 board (SIDE B)
(See page 23.)
E-F Balance Check
Connection:
Procedure:
1. Connect an oscilloscpe to test point TPO103 (TE1) and TP117
(VC) on the BD84 board.
2. Turn the power on.
3. Select the function “CD”.
3. Select the function “CD”.
4. Press three buttons of [ENTER], M , and
[SURRUUND MODE] simultaneously to set the CD service
mode.
mode.
5. Put the disc (YEDS-18) in to playback the number five track.
6. Press the . button. The message “TRAVERSE” is
displayed. (The tracking servo and the sledding servo are
turned OFF)
turned OFF)
7. Check the level B of the oscilliscope's waveform and the A
(DC voltage) of the center of the Traverse waveform.
Confirm the following :
A/B x 100 = less than
Confirm the following :
A/B x 100 = less than
± 22%
Traverse Waveform
8. Press the . button. The message “TRAVERSE” is
displayed. (The tracking servo and sledding servo are turned
ON)
Confirm the C (DC voltage) is almost equal to the A (DC
voltage) is step 5.
ON)
Confirm the C (DC voltage) is almost equal to the A (DC
voltage) is step 5.
9. To exit from this mode, perform as follows.
1)
Move the optical pick-up to the most inside track.
2) Press three buttons of x , [CLEAR], and [DISPLAY]
simultaneously. (cold reset)
simultaneously. (cold reset)
Notes:
• Always move the optical pick-up to most inside track
when exiting from this mode. Otherwise, a disc will not
be unloaded.
• Do not run the sled motor excessively, otherwise the gear
when exiting from this mode. Otherwise, a disc will not
be unloaded.
• Do not run the sled motor excessively, otherwise the gear
can be chipped.
Traverse Waveform
Checking Location: BD84 board (SIDE B) (See page 23.)
+
–
–
BD84 board
TP124 (RFAC)
TP117 (VC)
oscilloscope
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
TIME/DIV: 500 ns
level: 0.9
±
0.4 Vp-p
+
–
–
BD84 board
JPO103 (TE1)
TP117 (VC)
oscilloscope
0V
B
level: 1.0
±
0.5 Vp-p
Center of
the waveform
the waveform
A (DC
voltage)
0V
Tracking servo
Sled servo
ON
C (DC
voltage)
voltage)
Tracking servo
Sled servo
OFF
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