Sanyo CDF-R800 Service Manual page 33

c
1
TROUBLE SHOOTING
L
8. TES, HFL (Traverse signal)
In transferring pickup from inner track to outer track,
EF output from pickup should be so connected that
HFL and TES have phase relation as shown in the
figure below. TES comparator has about *1 OOmV
hysteresis at -polarity comparator against TESI
input. To pickup exclusively necessary signals out of
TE signals, band pass filter is configurated outside.
L
L
TES
TE
11.DEFECT
This normally maintain mirror surface level by con-
denser of LF2 (59pin), and when lack of EFM
signal (RFSM output) gets over 0.35V, outputs "H"
to DEF (49pin). When DEF (49pin) becomes "H",
tracking servo changes into THLD mode.
LF2 (59PIN)
I I
1 1
&
DEF(49PlN)~
12.Reset circuit
9. DRF (Beam level judgement)
When Vcc gets over about 2.8V, Power on Reset is
DRF becomes "H", when EFM signal (RFSM output)
cancelled.
is held at peak value by conde&er of PH1 (60pin)
and peak value of RFSM gets over 2.1V. Condenser
of PHI (60pin) is related to setting both DRF
constant when detected and RFAGC response.
DRF
--+
'e"
Pickup
position ~?
In focus
3.5V
2.lV
1.5V
10.In-focus judgement
This detects DEF+O.2V of focus error signal S
curve, and then judges focus zero cross (being in
focus) when S curve becomes REF.
I(J'
In focus
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