Adjustment - Kenwood DP-R792 Service Manual

DP-R792/R892/R4440
ADJUSTMENT
SETTING SETTING SETTING
Short~cireuit pins
TEST and turn the
power on to enter
the test mode.
Press the MANUAL S.
key P)to move th
pickup outwards.
ALIGNMENT
POINT
ALIGN FOR
On the power from
0.1 to 0.3m¥, when
the diffraction
grating is correct)
aligned with the RF
level of 1.0Vp-p
or more and
the TE (servo open)
level of 1.5Vp-p
or more, the pickup
is acceptable.
as ITEM
LASER POWER
TRACKING ERROR
BALANCE
Apply the sensor
section of the optical
power meter on the
pickup lens.
emits light. Then,
confirm that the
display is" 05".
Turn power switch
off and set the
unit to test mode
again.
Press the Dp key
to open the tray.
Load a test dise and
press the DW key.
hen press the CHECK
key. Confirm that
the display is "05".
Press the PLAY
key. Confirm that
the display
is" 05".
Connect an oscilloscopd
as follows.
CH1: RF (CN9-1)
CH2: TE CCN9-6)
Symmetry between
upper and lower
or DC=0+0.05V
Test dise
Type 4
Connect an oscilloscope
as follows.
CH1: RFCCN9-1)
CH2: TECCN9-6)
Opt imun
eye pattern
Test disc
Type 4
FOCUS ERROR
BALANCE
Test dise
Type 4
Apply signal of
1. 0kHz, 0.1V¥rms to
CN9 pin 2-8.
Test disc
Type 4
Apply signal of
1.0kHz, 0.1Vrms to
CN9 pin 5-6.
Two VTVMs should read
the same value.
Connect a LPF to CNQ Press the PLAY
key. Confirm that
the display
is" 05".
FOCUS GAIN
an oscilloscope
or two AC voltmeters.
Press the PLAY
key. Confirm that
the display
is" 05".
Two VTVMs should read
the same value.
Connect an LPF to CN9
TRACKING GAIN
an oscilloscope
or two AC voltmeters.
(Note) Type 4 disc: SONY YEDS-18 Test Disc or equivalent.
LPF: Around 47k2+390pF or so.
Steps 1~5 are in Test Mode.
(a) Laser Power
@
(d) Focus Gain and Tracking Gain Adj.
0.1~0.3mW Focus gain Adj.
Tracking gain Adj.
Optical power meter
15
DP-R792/R892/R4440
ADJUSTMENT
CH1 RF
1.0V/div
0.1V/div
CH2 only
(2usec/div)
2.0V/div
j~—0(v)
RF signal
0.5V/div
CH2 E.Spot
. CH2 T.Error
®@ RF signal and E.Spot signal in test mode (PLAY).
® if the diffraction grating has been adjusted properly,
the influence of triggering is observed on the E.Spot
waveform of approx. 18us after RF signal, in the form
of a projection.
{
AC coupling for
@ RF signal and T.Error signal; in test mode (Focusing
ON). (Disc type 4)
@ Adjust T.Error so that the waveform is symmetrical
above and below OV. (VR2)
@ RFF signal in test mode (PLAY).
@ Perform the tangential and focusing offset adjustments
so that each of the center cross points are focused into
one. point on the display. The crossing points above
and below the center shall also be displayed clearly.
16