Kenwood RXD-790 Service Manual page 15

3. Adjustment of CD player
INPUT
No. ITEM
SETTING
Step 1~4 are in TEST MODE
TEST MODE : While pressing the (TIME DISP.) key, plug the AC power cord into the AC outlet.
LASER
1
POWER
TRACKING
2 ERROR Test disc Type 4
BALANCE
FOCUS
Test disc Type 4
3 ERROR
BALANCE
Test disc Type 4
Apply signal of
TRACKING
4
1.2kHz, 50mVrms
GAIN
to CN2 pin5-6.
Note:
Type 4disc :SONY YEDS-18 Test Disc or equivalent.
LPF : Around 47kΩ + 390pF or so.
(a) Laser Power
Pickup
(c)
¶ RF signal and TE signal in test mode (Focusing servo
ON / Tracking servo OFF). (Disc Type 4)
¶ Adjust TE signal so that the waveform is symmetrical
in relation to VC. VR 2 (TE BALANCE)
15
ADJUSTMENT
OUTPUT
SETTING
Set the senor sec-
tion of the optical
–
power meter on the
pickup lens.
Connect an oscillo-
scope as follows.
CH1 : RF (CN2-1)
CH2 : TE (CN2-6)
GND : VC (CN2-4)
Connect an oscillo-
scope as follows.
CH1 : RF(CN2-1)
CH2 : FE(CN2-2)
GND : VC (CN2-4)
Connect a LPF to
CN2 pin 5-6 to
which connect an
oscilloscope or AC
voltmeters.
0.05~0.15 mW
Optical power meter
CH1
RF signal
VC
VC
CH2
TE signal
RXD-790/V860/V890
PLAYER ALIGNMENT
SETTING POINT
Press the"PLAY"key
to check that the dis- –
play is "03".
TE
Press the "PLAY"
BALANCE
key. Confirm the
VR2
display is"03".
Press the "PLAY" FE
key. Confirm that BALANCE
the display is"05" VR1
Press the "PLAY" TRACKING
key. Confirm that GAIN
the displays"05" VR3
(b) Tracking Gain Adj.
CN2
1
2
3
+ 4
1.2 kHz
5
50 mVrms
6
_
7
(d)
RF signal : AC coupled
¶ RF signal in test mode (PLAY).
¶ Perform the tangential and focusing offset are focused
into one point on the display. The crossing points
above and below the center shall also be looked clear-
ly.
ALIGN FOR FIG.
On the power
from.0.05 to
0.15mw. when the
diffraction grating is (a)
correctly aligned
with the RF level of
0.8Vp-p or more
Symmetry between
upper and lower or (c)
DC=0±25mV
Optimum eye pattern (d)
Two VTVMs should
read the same (b)
value.
GND
+
L.P.F. VTVM
+
L.P.F. VTVM