Zenith DV140 Service Manual page 19

E
Normal Audio output
when disc playback?
YES
Normal IR.VFD & Front
pannel key functions?
YES
TEST END
NO
Audio DAC received
correct data stream?
Normal Audio DAC out?
Check Audio
filter,amplify,mute
circuit.
Communications between
NO
IR.VFD Front pannel key &
MT1389D is normally?
Check the cable connection
on Front pannel.
3-9
NO
YES
NO
YES
NO
YES
Check connection between
MT1389D & Audio DAC.
Check the related circuit of
Audio DAC.
Check communication lines
on MT1389D.