NAD L55, Service Manual

Page: 18 / 55

2-9
Does tray open or close?
Does the pick-up
slide inner or outer
track?
Fig.1. SLED Driver waveform
Fig.2. Focus Driver waveform
Does
the voltage change
at PMD04 Pins 1, 2 more than
2V on the basis of
3.8V?
Pressing
the open/close key
repeatedly, check the voltage of IC2M1
Pins 13, 14 change
0V to 5V
Does
PMD03 Pin 7 change
high to low?
Does
the pick-up lens move up
and down?
Check Focus Driver output.
(IC201 Pin 83, IC2M1 Pins 37, 38)
Check SLED Driver output.
IC201 Pin 88 IC2M1 Pins 28, 29.
IC201 Pin 88 no output : IC201 is defective
IC2M1 Pin 18 no output : IC2M1 is defective
IC201 Pin 83 no output : IC201 is defective
IC2M1 Pins 1, 2 no output : IC2M1 is defective
DECK assembly is defective.
Slide the pick-up to
inner track.
.Power on
Check loading Part.
Push Pick-up to inner track to
the end by hand.
DECK assembly is defective.
(Limit sw)
check
µ
-COM Part.
Replace IC2M1.
No disc
B.
END
NO
NO
NO
NO
NO
NO
YES
YES
YES
YES
YES
YES