JVC VS-DT2000 Service Manual page 20

VS-DT2000
Flow of functional operation until TOC read
Power ON
Tracking error waveform at TOC reading
Approx.3sec
Pin 20 of
IC601(TEOUT)
Approx
1.8V
VREF
Tracking
servo
off states
Disc states
to rotate
Automatic measurement
of TE amplitude and
automatic tuning of
TE balance
1-20
Play Key
Automatic measurement of
Focus S-curve amplitude
Automatic measurement of
Tracking error amplitude
Tracking
Disc to be
servo
braked to stop
on states
Automatic tuning of
TOC reading
finishes
Tracking error balance
500mv/div
2ms/div
Fig.1
Slider turns REST
SW ON.
Automatic tuning
of TE offset
Laser ON
Detection of disc
Automatic tuning of
Focus offset
Disc is rotated
Focus servo ON
(Tracking servo ON)
Automatic tuning of
Focus error balance
Automatic tuning of
Focus error gain
Automatic tuning of
Tracking error gain
TOC reading
Play a disc
Check Point
Confirm that the voltage at the pin3
of CN611 is "H"\"L"\"H".
Confirm that the Focus error
S-curve signal at the pin 28 of
IC651 is approx.2Vp-p
Confirm that the signal from
pin 24 IC651(R808) is 0V as a
accelerated pulse during
approx.400ms.
Confirm the waveform of
the Tracking error signal
at the pin 20 of IC601 (R604)
(See Fig.1.)
Confirm the eys-pattern
at the lead of TP1.