Sanyo FISHER DVD-1500 Service Manual page 13

CHECK FLOW AND TROUBLE SHOOTING
(Automatic alignment block)
Layer jump
Automatic alignment block
Problem/symptom
Focus unstable
1 Susceptable to shock
Oscillatory noise from pickup
Squeaky noise while pickup is travelling
Excessively long time taken for alignment
2 Susceptable to shock
Oscillatory noise from pickup
Squeaky noise while pickup is travelling
3 Unable to align/disk error
4 Long time taken for alignment
An extract from "GENERAL FLOW"
Identifies disk
Sets mode
INIT processing of TC9461
Laser off 20 ms
Turns on laser.
Focus search
Automatic alignment
Tracking balance
Focus balance
Focus gain
Tracking gain
RF gain
DVD / CD
DVD
Internal circumference
optimization
Two-layer
One-layer or
two-layer
Two-layer
completed
One-layer
Check
focus servo system.
Check for signal flow
Check for signal flow
If not rotating with board, pickup need be analyzed.
tracking servo system.
Check for signal flow
Check for signal flow
If not rotating with board,pickup need be analyzed.
Check RF level.
Laser deteriorated? (Check laser current:R5100)
Check for dirt on lens
Check FWD.
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Tracking balance alignment
Rotates at a speed of twice that of CD.
100ms wait
DVD / CD
CD
DVD
TRACKING ON
SLED OFF
200ms wait
ADRESS CHECK
Focus balance alignment
Focus gain alignment
Tracking gain alignment
SLED ON
RF gain alignment
Waveform Schematic diagram Reference data
(24)~(27)
(20)~(23)
(2)(3)(4)
Sets to normal speed.
100ms wait
F
G, H
C, D, E
I Voltage table (2)