Sony HCD-VX88 Service Manual page 21

Note: Clear RF signal waveform means that the shape " " can be
clearly distinguished at the center of the waveform.
RF signal waveform
E-F Balance (1 Track Jump) Check
BD board
TP (TEO)
TP (VC)
Procedure:
1. Connect oscilloscope to TP (TEO) and TP (VC) board.
2. Turned Power switch on.
3. Load a disc (YEDS-18) and playback the number five track.
Press the hH button. (Becomes the 1 track jump mode.)
4.
5. Confirm that the level B and A (DC voltage) on the oscilloscope
waveform.
1 track jump waveform
0V
level=1.3 0.6Vp-p
A
x 100=less than ±22%
Specification level:
B
6. After check, remove the lead wire connected in step 1.
RF PLL Free-Run Frequency Check
Procedure :
1. Connect frequency counter to test point (XPCK) with lead wire.
BD board
TP (XPCK)
2. Turned Power switch on.
3. Put the disc (YEDS-18) in to play the number five track.
Confirm that reading on frequency counter is 4.3218MHz.
VOLT/DIV : 200mV
TIME/DIV : 500ns
level : 1.45 0.3Vp-p
oscilloscope
+
–
Center of
waveform
B
A (DC voltage)
Symmetry
frequency counter
+
–
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