Rf Level Check; E-F Balance (Traverse) Check - Sony HCD-MD5 Service Manual

5. Check the oscilloscope waveform (S-curve) is symmetrical be-
tween A and B. And confirm peak to peak level within 2.4 ± 0.7
Vp-p.
S-curve waveform
6. After check, remove the lead wire connected in step 2.
Note : • Try to measure several times to make sure that the ratio
of A : B or B : A is more than 10 : 7.
• Take sweep time as long as possible and light up the
brightness to obtain best waveform.

RF Level Check

BD (CD) board
TP (RF)
TP (VC)
Procedure :
1. Connect oscilloscope to test point TP (VC) and TP (RF) on BD
(CD) board.
2. Turned Power switch on.
3. Put disc (YEDS-18) in and press the · (CD) key.
4. Confirm that oscilloscope waveform is clear and check RF sig-
nal level is correct or not.
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 (Traverse) Check

BD (CD) board
TP (TEO)
TP (VC)
Procedure :
1. Connect the TP (TEI) and TP (VC) with lead wire.
2. Connect oscilloscope to test point TP (VC) and TP (TEO) on
BD (CD) board.
3. Turned Power switch on.
4. Put disc (YEDS-18) in and press the · (CD) key.
5. Confirm that the oscilloscope waveform is symmetrical on the
top and bottom in relation to 0 Vdc, and check this level.
symmetry
A
within 2.4 ± 0.7 Vp-p
B
oscilloscope
+
–
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
level: 1.3 ± 0.3Vp-p
oscilloscope
(DC range)
+
–
Traverse waveform
specified level : • —————— × 100 = less than ± 7%
• A+B= 300 ± 100 mVp-p
6. Remove the lead wire connected in step 1.
Focus/Tracking Gain Adjustment (RV102, RV103)
This gain has a margin, so even if it is slightly off. There is no prob-
lem.
Therefore, do not perform, this adjustment.
Please note that it should be fixed to mechanical center position
when you moved and do not know original position.
Adjustment Location :
[BD (CD) BOARD] – Side B –
IC102
FOK
TEI
IC101
RF
RV101
– 27 –
A
B
level: 300 ± 100 mVp-p
A–B
2 (A+B)
FEI
RV102
FEO
VC
IC104
TEO
RV103