Sanyo FISHER DVD-1500 Service Manual page 9

DVD P.W.BOARD OPERATION
(GENERAL FLOW)
Turn on power.
Depress open/close
switch.
Tray opens.
Place a disk
on tray.
Depress open/close
switch.
Tray close/closed
"LASER" lights.
Lowers lens
(approx. 400 ms).
Pickup returns.
SPINDLE motor
turns on.
8/12 cm
identification.
FG confirmation
Rotates at a speed of
approx. 0.7 time
that of CD
Lowers lens with
each IC in DVD mode
Measures FE level (a)
FE pulse 1 or 2
Lowers lens with in
LCD and DVD mode
Rotates at
a speed of two times
that of CD
Measures FE level (a)
2
FE pulses;
one or two
1
NO
(b)/(a)>1.5
YES
One-layer DVD
Sets one-layer
Sets CD circuit
DVD circuit
to pickup mode.
to pickup mode.
INIT processing of
TC9461
Laser off 20 ms
Laser on.
Lowers lens
Rotates SPINDLE at
a speed of twice
that of CD.
Waits for prescribed
number of rotations
to be completed.
Checks FG.
Raises lens.
FOCUS OK?
NO
YES
Waits for approx. 500 ms.
New disk?
Old
New
Layer jump
Tracking balance alignment
Rotates at a speed of twice that of CD.
Waits for 100 ms.
DVD/CD
CD
DVD
Sets to normal speed.
100ms wait
TRACKING ON
SLED OFF
200ms wait
ADDRESS CHECK
Focus balance alignment
Focus gain alignment
Tracking gain alignment
SLED ON
RF gain alignment
- 8 -
This is a basic flowchart.
Two-layer DVD
Sets two-layer
DVD circuit to
pickup mode
Optimization
CD
One-layer or
two-layer
Two-layer
One-layer
completed
Measures p oor playability varlue
READ-IN play
CD : TOC READ
DVD : CSS processing
DVD
Pickup moves outward. CD/DVD
Wait to PLAYBACK
Optimization
DVD/CD
CD
DVD
Measures error rate
OK
Error judgement
NG
Aligns tracking balance
OK
Error judgement
NG
EQB
OK
Error judgement
NG
EQF
OK
Error judgement
NG
Aligns tracking balance
OK
Error judgement
NG
TIME OUT:ERR.
Two-layer completed
CD
STOP