– 3 –
SECTION 1
SERVICING NOTES
1-1. WRITING FOCUS/TRACKING AUTO GAIN
DATA
In general for the CD players that use a digital servo IC, the focus/
tracking gain is automatically adjusted each time a disc is changed.
In this set, the gain in test disc (YEDS-18) has been written to a
nonvolatile memory (IC803: X24C01S) on the Display Board, and
therefore the gain is not readjusted even if a disc is changed.
Accordingly, always write auto gain data when replacing the Servo
Board, IC803 on Display Board, or optical pick-up.
1)Connect CN805 1 pin (IN/OUT SW) and 6 pin (GND) on
Display Board.
Under this condition, the set will operate even when the disc lid
is open (or Key Board is not connected).
2)Connect TP (ADJ: CN105 3 pin) on Servo Board to GND, and
TP (VC: CN108 2 Pin) to TP3 (TEI: IC105 @¶ pin) with lead
wires respectively.
3)Connect an oscilloscope to TP (TE: CN108 1 pin).
4)Insert the test disc (YEDS-18), turn on POWER switch, and
play fifth music with · (PLAY) and AMS Keys on the
Remocon.
5)Adjust RV101 so that the waveform on oscilloscope is verticolly
symmetric with respect to the A [Vdc], and also its level is 1.3 ±
0.6 Vp-p.
At this time, A/B × 100 = ± 22 (%) or less
6)The auto gain data are written when a lead wire between TP
(ADJ: CN105 3 pin) and GND is removed.
Note:If the POWER switch was turned on without connecting TP
(ADJ) to the GND, auto gain data are not written to the
memory even if a disc is inserted, but the previous data saved
in the memory are used as focus/tracking data.
1-2. AF MODE
With the TP (AFJ: CN105 2 Pin) connected to the GND on Servo
Board, turn on the POWER switch, and the AF mode is activated
and the following checking can be made.
1-2-1. FL tube check
All tubes turn on, then if · button is pressed, the display will be
as shown below. (Segment ON 1)
(Segment ON 1)
6
16
2
12
8
18
4
14
10
20
(Segment ON 2)
0Vdc
B
A
symmetric
level: 1.3 ± 0.6 Vp-p
IF P button is pressed, the display will be as shown below. (Seg-
ment ON 2)
+
–
SERVO board
TP (TE)
TP (VC)
Oscilloscop
If STOP p is pressed, all tubes turn on again.
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