NAD T585 Service Manual page 18

C
Laser turns on when NO
reading disc?
YES
NO
Put disc in?
YES
NO
Disc ID is correct?
YES
NO
Does spindle rotate?
YES
D
DVDLD or CDLD
output properly?
YES
Collector voltage of
power transistor is OK?
YES
Check cable connection between
transistor ouput and pick-up
head.
Laser off
Proper RFSIN signal
on CXD1881?
YES
Check DVDLD & CDLD signal
Proper SPWM signal on
CXD1885Q
YES
SP+ & SP- output
properly?
YES
Check the cable connection
between spindle and main PCBA.
3-8
Check the laser power circuit
NO
on CXD1881 and connecting to
power transistor.
NO
Check the related circuit on
laser power transistor
NO
Check the related circuit
on CXD1881 RFSIN signal.
NO Check SPWM related
circuit on CXD1885Q.
Check the spindle control
NO
amp circuit of motor
driver.