Sony HCD-H77 - CD SECTION Adjustments

CD SECTION
Adjustment Location : main board —component side— Note:
1. CD Block basically constructed to operate with-
out adjustment. Therefore, check each item in
sw OSC :
VOLTAGE FM TUNED FM DISCRIMINATOR order given.
as INDICATION LIGHTING ALIGNMENT 2. Use YEDS-18 disc (3-702-101-01) unless otherwise
ee ray LEVEL ADJ —
T2, CT22 RV81 IFT82, TP81 indicated.
3. Use the oscilloscope with more than 10MS2 im-
pedance.
4. Clean an object lens by an applicator with neutral
TB1 3 :
ANTENNA detergent when the signal level is low than
specified value with the following checks.
sw
TRACKING dik
nee S Curve Check
oscilloscope
MW(AM)TUNED BD board
J701 INDICATION LIGHTING ie
VIDEO/AUX LEVEL ADJ —s
(HCD-H70) TP (FEO) o=<— °F
PHONO TP (VC) omw—to-
(HCD-H66/H77/ Procedure :
H1200/H1400)
1. Connect oscilloscope to test point TP (FEO) on
BD board.
2. Connect between test point TP (FES) and TP
(VC) by lead wire.
3. Turned Power switch on and actuate the focus
serch. (actuate the focus serch when disc table is
moving in and out.)
4. Check the oscilloscope waveform (S curve) is
symmetrical between A and B. And confirm peak
to peak level within 3+1Vp-p.
S curve waveform symmetry
step 2.
Note: + Try to mesure 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
oscilloscope
BD board
—S
TP (RF) O<— 0+
TP (VC) O=t——0 -
Procedure :
1. Connect oscilloscope to test point TP (RF) on
BD board.
2. Turn Power switch on.
3. Put disc (YEDS-18) in and playback.
4. 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 distinguished at the center of the wave-
form.
VOLT/DIV : 200mV
TIME/DIV : 500nS
level :
RF signal waveform
MAMAAAAAA?
\}
Wy)
i
'
X)
49000000009
1000000000000 +0.2
E-F Balance Check
oscilloscope
BD board
mS
TP(TEO) O——o}
TP(vC) ow—lo-
Procedure :
1. Connect test point TP (ADJ) to ground and TP
(TES) to TP (VC) with lead wire.
2. Connect oscilloscope to test point TP (TEO) on
BD board.
Turn Power switch on.
Put disc (YEDS-18) in and playback.
5. Confirm that the osilloscope waveform is sym-
metrical on the top and bottom in relation to OV,
and check this level.
Traverse oscilloscope
symmetry
level: 2£1Vp-p
6. Remove the lead wire connected in step 1.
RF PLL Free-run Frequency Check
Procedure :
1. Connect frequency counter to test point (PCK)
with lead wire.
Main beat frequency counter
Finds om fe —
TP (PCK) se
Turn Power switch on.
3. Confirm that reading on frequency counter is
4. 3218MHz.
Focus/Tracking Gain
This gain has a margin, so even if it is slightly off.
There is no problem.
Therefore, do not perform, this adjustment.
Please note that it should be fixed to mechanical cen-
ter position when you moved and do not know
original position.
Adjustment
(BD board
pL Ld