BBK DK1410SI - Page 49

8. Troubleshooting process for no sound of MIC is shown as the following figure 3.3.2.8:
No sound of MIC
Both have no sound
Use remote controller to
open MIC items
N
Whether MIC item
has been opened.
Note
Whether power
supply of 4558, CD4052
and 5340 is
normal
Check and repair the
corresponding power
supply circuit
N
Y
Use oscillograph
to test whether pin 6
of N1 (4558) has
input
Check flat cable of XP201, XS201
N
Y
Whether pin 7
of N1 has output
Y
Whether C6, R4
are normal
Change C6, R4
N
N
Change N1
Whether pin 28
of XS207 on power
amplifier board
has output
Y
Whether two
ends of R226 (near 207)
have signal
Y
Check whether flat
cable is well inserted
or whether R226 has
broken circuit
Change MT1389
One has no sound, for instance,
MIC1 has no sound
Check XP201, XS201 and
flat cable or change MIC
holder
N
Check whether
pin 3 of XS201 has
MIC1 signal
Check R1 C1
Y
N
Y
Note : MIC items can be selected only when
playing disc.
: Speak with MIC at the same time when
measuring signal everywhere.
N
Whether pin 3,
13 of N5 (CD4052)
have output
Whether R87 is normal
Y
Change N7
Change or well weld
R87 again
Y
N
Change N5 (CD4052)
N
Figure Troubleshooting flow chart for no sound of MIC
3.3.2.8
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