Mitsubishi Electric DD-8020, Руководство по обслуживанию

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Disc kind misjudgement
(Initial setting is NG.)
Replace pickup head.
Lens cleaning.
Check IC502.
Are FE and RFSB
signals for each disc normal?
Check peripheral
circuit of IC306.
2-2
Y
N
Check laser operating current.
Check laser current.
I min lop I max
Check pins 13, 14
and 15 of IC502
serial bus.
Check peripheral
circuits of IC502,
Q501, Q502.
Check solder removal
of the short land for
laser diode protection.
Check FE and RFSB signal
lop I max
lop I min
3
Check wiring for
pickup head.
Replace pickup
mechanism.
Y
Y
N
lop 200 mA
Laser operating current
DVD Iop
DVD Iop = Voltage between (E559 and E534) /10
W
CD Iop = Voltage between (E536 and E534) /10
W
CD Iop
min
20mA
20mA
35mA
45mA
60mA
80mA
typ max
CAUTION
The laser ray emitting out from the pickup head is very harmful to your eyes.
Keep your eyes from the objective lens at least 300mm distance during the pickup head operating.
When you perform solder removal work, please turn OFF a set power supply and perform the
ground of human body and a tool.
To turn on each laser diode forcibly, press the following buttons on the remote controller.
DVD LD:
CD LD:
After checked the laser current, press POWER or OPEN/CLOSE button to turn it off.
ZOOM, 0, 3, 0, ZOOM
ZOOM, 0, 3, 1, ZOOM
Fig. 1-3-4
Fig. 1-3-5
TP405 FE signal
1.65V
V : 500 mV/div
H : 2 ms/div
TP503 RFSB signal
DVD single (single-layer) disc
detection waveform
V : 500 mV/div
H : 2 ms/div
DVD dual (dual-layer) disc
detection waveform
V : 500 mV/div
H : 2 ms/div
CD disc
detection waveform
Fig. 1-3-6 Fig. 1-3-7 Fig. 1-3-8
1-9