Flow Of Functional Operation - JVC UX-A52 Service Manual

UX-A52
Flow of functional operation until TOC read (CD)
Power ON
Tracking error waveform at TOC reading
Approx.3sec
pin 25 of
IC601(TE)
Approx
1.8V
VREF
Tracking
servo
off statas
Disc statas
to rotate
Automatic measurement
of TE amplitude and
automatic tuning of
TE balance
1-28
Slider turns REST
Power Key
Automatic tuning
of TE offset
Detection of disc
Automatic tuning of
Automatic measurement of
Focus A-curve amplitude
Automatic measurement of
Tracking error amplitude
Tracking
Disc to be
servo
braked to stop
Automatic tuning of
on statas
TOC reading
Tracking error balance
finishes
500mv/div
2ms/div Fig.1
SW ON.
Laser ON
Foucus 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
Check to see if the voltage at the
pin 72 of IC701 or pin 5 of CN602
becomes 0 V for an instant. (The
moment the switch is turned on,
the voltage becomes 0 V.)
Make sure of the H level at
the pin 40 of IC603.
Confirm that the Focus error
S-curve siganl at the pin28 of
IC603 is approx.2Vp-p
Confirm that the siganl from
pin24 IC603 (R645) is 0V as
a accelerated pulse during
approx.400ms.
Make sure that the TE
signal (1.8 Vp-p approx.)
indicating the tracking
servo off status is output
from the pin 25 (one side
of R609) of IC601.
Confirm the eys-pattern
at the lead of TP602