NAD T534AH Service Manual page 16

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
LD01 or LD02 output
properly?
YES
Collector voltage of
power transistor is OK?
YES
Check cable connection between
transistor ouput and pick-up
head.
Laser off
Proper RFL signal
on MT1389?
YES
Check LDO1 & LDO2 signal
Proper DMSO signal on
MT1389
YES
SP+ & SP- output
properly?
YES
Check the cable connection
between spindle and main PCBA.
3-7
Check the laser power circuit
NO
on MT1336 and connecting to
power transistor.
NO
Check the related circuit on
laser power transistor
NO Check the related circuit
on MT1389 RFL signal.
NO Check DMSO related
circuit on MT1389.
Check the spindle control
NO
amp circuit of motor
driver.