Sanyo FISHER DVD-1500 Service Manual page 11

CHECK FLOW AND TROUBLE SHOOTING
(LASER ON/ 8/12 cm identification)
An extract from "GENERAL FLOW"
Turn on power.
Tray close/closed
"LASER" lights.
Pickup returns.
8/12 cm identification
Identifies disk
Sets mode
INIT processing of TC9461
Laser off 20 ms
Laser on.
Focus search
LASER ON/ 8/12 cm identification
Problem/symptom
1 "LASER" does not light.
2 No pickup return operation. Check SLED voltage and timing. Check limit switch.
3 Disk does not rotate.
4 Disk rotates at a high speed. Check SPDL FO.
Laser focus search after initial processing.
Problem/symptom
1 Disk error due to erroneous Check disk identifying waveform in LASER mode.
disk identification
2 Focus servo inactive
3 Disk unreadable
"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
Check
Check LASER ON timing and drive transistor voltage.
Check VCC2 at pin 36 of IC501 TA1254.
Check for short-circuiting of LASER (excessive current [R5100],
though protected by fixture)
Check for LASER destruction. If so, check LASER current (R5100).
Check micon interface (SCB, SCL & SCD)
Check FRST (LASER to be active at LOW).
Check signal FLOW.
Check and trace control signals.
Check SPINDLE voltage and timing.
Check SPINDLE voltage and timing.
Turn off power at once.
Check SPINDLE/SLED servo system.
Check
Check waveforms up to "focus ok" with each disk. (34)(35)(37)(38)
Check pin 43 of IC701 TC9461.
Check DFTN.
DFTN:normally High, at SCRATCH:Low
Data output normal? CN801/IC802
Check DVD/*CD signal (CD/*DVD).
DVD:High, CD:Low
(IC900 pin 1, IC501 pin 35, Q6001 base)
Check SEL signal (must be High when laser is on).
- 10 -
(Laser focus search after initial processing.)
An extract from "GENERAL FLOW"
Turn on power.
Tray close/closed
"LASER" lights.
Pickup returns.
8/12 cm identification
Identifies disk
Sets mode
INIT processing of TC9461
Laser off 20 ms
Laser on.
Focus search
Automatic alignment
Tracking balance
Focus balance
Focus gain
Tracking gain
RF gain
CD
DVD / CD
Waveform
(18)(19)
(28) ~ (31)
(35) ~ (37)
(44) ~ (46)
(44) ~ (46)
Waveform
2,(34) ~ (38)
(28) ~ (31)
2,(36)
(40) ~ (43)
(44) ~ (46)
(28) ~ (31)
Turns on laser.
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.
Schematic diagram Reference data
L
TA1254 voltage
table (2)
L
L
I , I'
A , B Voltage table (4)
A , B Voltage table (4)
Schematic diagram Reference data
F
L
F
C,D,E
C,D,E
Voltage table
L
(8)