22
SECTION 6
ELECTRICAL CHECK
Note:
Power supply voltage: DC14.4 V (more than 3 A).
• FOCUS BIAS CHECK
– RF BOARD –
(Component Side)
Procedure:
1. Connect the oscilloscope to TP (RFO) and TP (VC) on the RF
board.
2. Put the set into play mode by loading the disc.
3. Confirm that oscilloscope waveform is clear and check RF
signal level is correct or not.
Note:
Clear RF signal waveform means that the shape “
◊
” can be clearly distin-
guished at the center of the waveform.
• TRACKING OFFSET CHECK
– RF BOARD –
(Component Side)
Procedure:
1. Connect the oscilloscope to TP (TE) and TP (VC) on the RF
board.
2. Put the set into play mode by loading the disc.
3. Press the
.
AMS
>
button, and check the traverse wave-
form*.
4. Confirm that the oscilloscope waveform is symmetrical on the
top and bottom in relation to 0 V dc, and check this level.
* Traverse waveform: This is the tracking error wave form appears
when crossing the track.
oscilloscope
+
–
TP (VC)
TP
(RFO)
IC101
RF signal waveform
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
level: 1.4
±
0.3 Vp-p
oscilloscope
+
–
TP (VC)
TP (TE)
IC101
A
B
0 V
A=B
traverse waveform
(100 track jump waveform)
VOLT/DIV : 500 mV
TIME/DIV : 2 ms
Center : 0 V
Traverse waveform
Содержание CDX-434RF - Compact Disc Changer System
Страница 51: ...51 MEMO ...