Sony MHC-DX90 Service Manual page 26

HCD-DX90
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 gG 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
x 100=less than ±22%
A
Specification level:
B
6. After check, remove the lead wire connected in step 1.
RF PLL Free-run Frequency
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.
20
VOLT/DIV : 200mV
TIME/DIV : 500ns
level : 1.45 ± 0.3Vp-p
oscilloscope
+
–
Center of
waveform
B
A (DC voltage)
Symmetry
frequency counter
+
–
Adjustment Location:
[BD BOARD] (Conductor Side)
TP
(AGCCON)
12
1
TP
IC103
(TEO)
24
40
TP
41
(FEO)
TP
(FEI)
TP
(VC)
TP
(RF)
TP
(XPCK)
21 20
1
IC101
80
61
60
TP
(DGND)