NAD L55 Service Manual page 18

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